1.
Which of the following statements are true of Inertia? List all that apply.
Correct Answer
D. All objects have inertia and more massive object has more inertia than a less massive object.
Explanation
Inertia is not a force, but rather a property of matter. It is the tendency of an object to resist changes in its motion. This property allows stationary objects to remain at rest and moving objects to continue moving at a constant velocity unless acted upon by an external force. Additionally, inertia is a property that all objects possess, and the amount of inertia an object has is directly related to its mass. Therefore, more massive objects have more inertia than less massive objects.
2.
Which of the following statements are true of the quantity mass List all that apply.
Correct Answer
A. Mass depends on how much stuff is present in an object and the mass of an object is mathematically related to the weight of the object.
Explanation
Mass depends on how much stuff is present in an object, meaning that the amount of matter in an object determines its mass. Additionally, the mass of an object is mathematically related to its weight. This relationship is given by the equation weight = mass x acceleration due to gravity. Therefore, the correct statement is that mass depends on how much stuff is present in an object and the mass of an object is mathematically related to the weight of the object.
3.
Which of the following statements are true of the quantity weight? List all that apply.
Correct Answer
A. The weight of an object is dependent upon the value of the acceleration of gravity.
Explanation
The weight of an object is equal to the force of gravity acting upon the object. It is computed by multiplying the object's mass by the acceleration of gravity (g) at the given location of the object. If the location of the object is changed, say from the Earth to the moon, then the acceleration of gravity is changed and so is the weight. It is in this sense that the weight of an object is dependent upon the acceleration of gravity.
4.
Which of the following statements are true of an object that experiences balanced forces (or unbalanced forces)? List all that apply.
Correct Answer
D. None of the above.
Explanation
An object that experiences balanced forces has no net force acting on it, meaning the forces are equal in magnitude and opposite in direction. If a person is moving to the right, the forces acting upon them could be balanced if there is an equal and opposite force acting in the opposite direction. A balance of forces is demonstrated by an object that is not changing its state of motion, whether it is moving at a constant velocity or at rest. It does not necessarily have to be slowing to a stop. It would not take an unbalanced force to keep an object in motion, as an object can continue to move with balanced forces if it is already in motion. Therefore, the correct answer is "None of the above."
5.
Consider Newton's first law of motion to determine which of the following statements are true? List all that apply.
Correct Answer
A. Newton's first law of motion is applicable to both moving and non-moving objects.
Explanation
Absolutely true. Like all true scientific laws, they govern all objects. In the case of Newton's first law of motion: An object that is nonmoving remains at rest (unless acted upon by an unbalanced force) and a moving object will continue in its motion at a constant velocity (unless acted upon by an unbalanced force).
6.
Which of the following statements are true of the concept of force? List all that apply.
Correct Answer
A. A force is a push or pull exerted upon an object which results from the interaction of that object with its environment.
Explanation
This is a great definition of force.
7.
Consider Newton's second law of motion to determine which of the following statements are true? List all that apply.
Correct Answer
B. If an object is moving to the right and slowing down, then the net force on the object is directed towards the left.
Explanation
An object which is slowing down has an acceleration which is directed opposite the motion of the object. So an object which moves to the right and slows down experiences a leftward acceleration and therefore a leftward net force.
8.
The anount of net force required to keep a 5-kg object moving rightward with a constant velocity of 2 m/s is ____.
Correct Answer
A. 0 N
Explanation
Net force is always mâ€¢a. In this case, the velocity is constant so the acceleration is zero and the net force is zero. Constant velocity motion can always be associated with a zero net force.
9.
A golf pro places a ball at rest on the tee, lines up his shot, draws back his club, and lets one rip. During the contact of the golf club with the golf ball, the force of the club on the ball is ____ the force of the ball on the club and the acceleration of the club is ____ than the acceleration of the ball.
Correct Answer
B. Equal to, greater than
Explanation
For every action, there is an equal and opposite reaction force. In this case, the force on the club is equal to the force on the ball. The subsequent accelerations of the interacting objects will be inversely dependent upon mass. The more massive club will have less acceleration than the less massive ball.
10.
A helicopter must have two sets of blades in order to fly with stability.
Correct Answer
C. Third Law (action-reaction)
Explanation
C - As the helicopter blades spin and push air in one direction, the air pushes the blades in the opposite direction; the result is that the helicopter can begin to rotate about the axis of the blade. To counteract this rotation, a second set of blades is required.
11.
If you were in an elevator and the cable broke, jumping up just before the elevator hit the ground would not save you. Sorry.
Correct Answer
A. First Law (inertia)
Explanation
A - An object moving downwards will continue to move downwards unless acted upon by an unbalanced force. If you make an effort to supply such a force in an attempt to suddenly alter the direction of your motion, then you are creating a greater velocity change than if you merely hit the ground and stopped. If this greater velocity change occurred suddenly (in the same amount of time as the stopping of you and the elevator), then you would experience a greater acceleration, a greater net force, and a greater ouch mark than if you had merely hit the ground and stopped.
12.
You usually jerk a paper towel from a roll in order to tear it instead of pulling it smoothly.
Correct Answer
A. First Law (inertia)
Explanation
A - The paper towel is at rest and resists changes in its at rest state. So if you apply a sudden force to one of the paper towel sheets, the great mass of the remainder of the roll will resist a change in its at rest state and the roll will easily break at the perforation.
13.
A student desk changes the amount of force it puts on other objects throughout a school day.
Correct Answer
C. Third Law (action-reaction)
Explanation
C - As a student sits in the seat, they are applying a downward force upon the seat. The reaction force is that the seat applies an upward force upon the person. A weightier person will apply more downward force than a lighter person. Thus, the seat will constantly be changing the amount of reaction force throughout the day as students of different weight sit in
14.
Heavy objects are not easier to move around in a horizontal fashion on the Moon than on the Earth.
Correct Answer
A. First Law (inertia)
Explanation
A - All objects have inertia or a tendency to resist changes in their state of motion. This inertia is dependent solely upon mass and is subsequently not altered by changes in the gravitational environment. To move an object horizontally, one must apply a force; this force will be resisted by the mass or inertia of the object. On the moon, the object offers the same amount of inertia as on Earth; it is just as difficult (or easy) to move around.
15.
The stronger, heavier team in a tug-of-war does not create a larger tension in the rope than the weaker, lighter team.
Correct Answer
C. Third Law (action-reaction)
Explanation
C - A rope encounters tension when pulled on at both ends. The tension in the rope is everywhere the same. If team A were to pull at the left end, then the left end would pull back with the same amount of force upon team A. This force is the same everywhere in the rope, including at the end where team B is pulling. Thus team B is pulling back on the rope with the same force as team A. So if the forces are the same at each end, then how can a team ever win a tug-of-war. The way a stronger team wins a tug-of-war is with their legs. They push upon the ground with a greater force than the other team. This force upon the ground results in a force back upon the team in order for them to pull the rope and the other team backwards across the line.
16.
1. ______ is a unit of speed:
Correct Answer
A. M/s
Explanation
The unit m/s is commonly used to measure speed. It represents the distance traveled in meters divided by the time taken in seconds. This unit is widely used in scientific and everyday contexts to express the rate at which an object or person is moving. It is a fundamental unit in the International System of Units (SI) and is preferred over other units like km/h or mph in scientific calculations and measurements.
17.
4. ______________ describes how fast something is
going, whereas, __________ describes how fast something is going and in a
certain direction.â€¨
Correct Answer
A. Speed, velocity
Explanation
Speed is a measure of how fast something is going, while velocity not only measures the speed but also takes into account the direction in which the object is moving. Speed is a scalar quantity as it only has magnitude, while velocity is a vector quantity as it has both magnitude and direction. Therefore, speed describes how fast something is going, whereas velocity describes how fast something is going and in a certain direction.
18.
8. The ______ of a distance versus time graph is
speed.â€¨
Correct Answer
A. Slope
Explanation
The slope of a distance versus time graph represents the rate at which the distance is changing with respect to time. In other words, it indicates the speed or velocity of the object. A steeper slope indicates a higher speed, while a flatter slope indicates a slower speed. Therefore, the correct answer is slope.
19.
9. The SI unit for speed is the ________.â€¨
Correct Answer
B. M/s
Explanation
The SI unit for speed is meters per second (m/s). This unit represents the distance traveled in meters divided by the time taken in seconds. It is commonly used in scientific and engineering calculations to measure the rate at which an object moves. The other options, such as in/hour and cm/min, are not SI units for speed and are not widely used in scientific contexts.
20.
Which falls faster if there is no air resistance?
Correct Answer
C. All ojects fall at the same speed
Explanation
In the absence of air resistance, all objects fall at the same speed. This is because the force of gravity acts equally on all objects regardless of their size or weight. The acceleration due to gravity is constant and independent of the mass of the object. Therefore, a heavier or bigger object will experience the same acceleration and fall at the same speed as a lighter or smaller object.
21.
Who proved that objects of different mass fall at the same rate by dropping two cannonballs of different masses from the top of the leaning tower of Piza. The crowd was surprised to see that the two cannonballs reached the ground at the same time.
Correct Answer
B. Galileo
Explanation
Galileo proved that objects of different mass fall at the same rate by dropping two cannonballs of different masses from the top of the leaning tower of Piza. The fact that the two cannonballs reached the ground at the same time surprised the crowd.
22.
All objects accellerate toward the earth at __________.
Correct Answer
C. 9.8 meters per second per second
Explanation
The correct answer is 9.8 meters per second per second. This is because all objects accelerate towards the Earth due to the force of gravity. The acceleration due to gravity is approximately 9.8 meters per second per second, which means that the velocity of an object falling towards the Earth increases by 9.8 meters per second for every second it falls.
23.
If you were to drop a feather and a marble right now, the marble will fall fall faster. Why?
Correct Answer
A. Air resistance
Explanation
The correct answer is air resistance. When objects fall, the force of gravity pulls them downwards. However, air resistance acts in the opposite direction and slows down the fall of objects. In the case of the feather and the marble, the feather has a larger surface area and is more affected by air resistance, causing it to fall slower compared to the marble. The marble, being denser and having a smaller surface area, experiences less air resistance and falls faster.
24.
How would you calculate the force acting on a falling object?
Correct Answer
C. The force of gravity minus the force of air resistance
Explanation
To calculate the force acting on a falling object, you need to subtract the force of air resistance from the force of gravity. This is because the force of gravity pulls the object downwards, while the force of air resistance opposes the motion and acts in the opposite direction. By subtracting the force of air resistance from the force of gravity, you can determine the net force acting on the object as it falls.
25.
Which law is this: The accelleration of an object depends on the mass of the object and the force applied.
Correct Answer
B. Newton's second law of motion
Explanation
This statement describes Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force applied to it and inversely proportional to its mass. In other words, the greater the force applied to an object, the greater its acceleration will be, and the greater the mass of an object, the smaller its acceleration will be for a given force.
26.
Which law is this: Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.
Correct Answer
C. Newton's third law of motion
Explanation
This statement describes Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. It explains that when one object exerts a force on another object, the second object will exert a force back on the first object that is equal in magnitude but opposite in direction. This law is fundamental in understanding the interactions between objects and the forces they exert on each other.
27.
How does a rocket engine work and which of Newton's laws of motion is involved.
Correct Answer
A. The rocket engine pushes gases downward so the gases push the rocket upward with an equal force. Newton's Third Law
Explanation
The correct answer explains that a rocket engine works by pushing gases downward, which in turn pushes the rocket upward with an equal force. This is an example of Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction.
28.
Which Law is this: An object at rest remains at rest and an object in motion remains in motion at a constant speed and in a straight line unless acted upon by an unbalanced force.
Correct Answer
A. Newton's first law of motion
Explanation
This statement describes Newton's first law of motion, also known as the law of inertia. It states that an object will continue to stay at rest or in uniform motion unless an external force acts upon it. This law is often summarized as "an object at rest stays at rest, and an object in motion stays in motion."
29.
If we are not moving then there are no forces acting on us.
Correct Answer
B. False
Explanation
The force of gravity is always acting on us.
30.
Friction is a force.
Correct Answer
A. True
Explanation
Friction is a force that opposes the motion of objects in contact with each other. When two surfaces rub against each other, the irregularities in their surfaces create resistance, resulting in the force of friction. This force can either slow down or stop the motion of an object. Therefore, it is correct to say that friction is a force.
31.
The formula for speed is distance divided by time.
Correct Answer
A. True
Explanation
The formula for speed is indeed distance divided by time. This formula is commonly used to calculate the rate at which an object is moving. By dividing the distance traveled by the time taken to cover that distance, we can determine the speed of the object. Therefore, the statement "The formula for speed is distance divided by time" is true.
32.
If an object is not moving then the forces on it are unbalanced.
Correct Answer
B. False
Explanation
Unbalanced forces cause movement in the direction of the force.
33.
If an object has a net force of 0 then it is not moving.
Correct Answer
A. True
Explanation
If an object has a net force of 0, it means that all the forces acting on it are balanced and cancel each other out. In this case, the object is not experiencing any acceleration and therefore, it is not moving. This is because according to Newton's first law of motion, an object at rest or in motion will stay that way unless acted upon by an external force. Since there is no net force acting on the object, it remains at rest or continues to move at a constant velocity.
34.
According to this distance vs time graph the object is
Correct Answer
C. Moving at a constant speed
Explanation
Based on the given distance vs time graph, the object is moving at a constant speed because the distance covered by the object is increasing at a steady rate over time. There are no changes in the slope of the graph, indicating that the object is not accelerating or decelerating. Therefore, the object is maintaining a constant speed throughout its motion.
35.
Between what two points is the object accerating?
Correct Answer
A. 0-A
Explanation
The object is accelerating between point 0 and point A.
36.
Where on this graph is the object stopped?
Correct Answer
D. This graph does not show the object stopped.
Explanation
If it showed the object stopped it would have a horizontal line at the X axis.
37.
If a mass is at rest, what must be applied to cause it to move?
Correct Answer
D. Force
Explanation
To cause a mass at rest to move, a force must be applied. Force is a physical quantity that can cause an object to accelerate or change its state of motion. In this case, the force applied will overcome the inertia of the object and initiate its movement. The other options, such as kilograms, speed, and vectors, are not directly related to causing an object at rest to move.
38.
How much force must be applied to a 4 kilogram mass to cause it to accelerate at 2 m/?
Correct Answer
B. 8 N
Explanation
To calculate the force required to accelerate an object, we can use Newton's second law of motion, which states that force is equal to mass multiplied by acceleration. In this case, the mass is given as 4 kilograms and the acceleration is given as 2 m/sÂ². By multiplying these values together (4 kg * 2 m/sÂ²), we find that a force of 8 N is required to cause the 4 kilogram mass to accelerate at 2 m/sÂ². Therefore, the correct answer is 8 N.
39.
Change in position is called ____________.
Correct Answer
B. Displacement
Explanation
Displacement is the correct answer because it refers to the change in position of an object. It is a vector quantity that takes into account both the magnitude and direction of the change in position. Velocity, on the other hand, refers to the rate at which an object's position changes with respect to time, while rate is a general term that can refer to various types of measurements or quantities.
40.
The change of velocity over time is called ___________.
Correct Answer
A. Acceleration
Explanation
Acceleration is the correct answer because it refers to the change in velocity over time. Velocity is a vector quantity that includes both speed and direction, so when there is a change in velocity, it means there is a change in either speed, direction, or both. Acceleration can be positive or negative, depending on whether the velocity is increasing or decreasing. It is measured in units of distance per time squared, such as meters per second squared (m/sÂ²).
41.
The acceleration due to gravity at or near the earth's surface is ______ m/s^{2}.
Correct Answer
C. 9.8
Explanation
The acceleration due to gravity at or near the earth's surface is 9.8 m/s2. This value is a constant and represents the rate at which objects accelerate towards the Earth when in free fall. It is denoted by the symbol "g" and is approximately 9.8 m/s2 on average. This means that for every second an object falls, its velocity increases by 9.8 m/s.
42.
The SI units of force are called _____________.
Correct Answer
A. Newtons
Explanation
The SI units of force are called Newtons. Newton is the unit of force in the International System of Units (SI). It is defined as the force required to accelerate a one-kilogram mass by one meter per second squared.
43.
1 Newton is equal to ___________________.
Correct Answer
A. 1 kg*m/s^2
Explanation
The correct answer is 1 kg*m/s^2. This is because Newton is the unit of measurement for force in the International System of Units (SI). It is defined as the amount of force required to accelerate a mass of 1 kilogram by 1 meter per second squared. Therefore, 1 Newton is equal to 1 kg*m/s^2.
44.
Gravity makes the Earth rotate around the sun.
Correct Answer
A. True
Explanation
Gravity is the force that keeps objects in orbit around each other. In the case of the Earth and the sun, the gravitational force between them causes the Earth to continuously move in a curved path around the sun. This motion is what we perceive as the Earth rotating around the sun. Therefore, the statement that gravity makes the Earth rotate around the sun is true.
45.
Who discovered gravity?
Correct Answer
A. Isaac newton
Explanation
Isaac Newton is credited with discovering gravity. He formulated the law of universal gravitation and explained how objects are attracted to each other. Newton's work on gravity revolutionized the field of physics and laid the foundation for our understanding of the forces that govern the motion of objects on Earth and in space. His discoveries and theories have had a profound impact on scientific advancements and continue to be widely studied and applied today.
46.
Gravity is a friction force.
Correct Answer
B. False
Explanation
Gravity is not a friction force. Gravity is the force of attraction between two objects with mass. It is a fundamental force that exists between all objects with mass in the universe. Friction, on the other hand, is a force that opposes the relative motion between two surfaces in contact. While gravity can affect the motion of objects, it is not considered a friction force.
47.
Everything has gravity.
Correct Answer
A. True
Explanation
Gravity is a natural force that attracts objects with mass towards each other. It is a fundamental property of matter and is present in everything that has mass. Therefore, it can be concluded that everything has gravity, making the statement true.
48.
Gravity is the force that
Correct Answer
B. Keeps the Earth orbiting around the sun.
Explanation
Gravity is the force that keeps the Earth orbiting around the sun. This is because gravity is the attractive force between two objects with mass, and it is responsible for holding celestial bodies in their orbits. In the case of the Earth and the sun, the gravitational force between them keeps the Earth in a stable orbit around the sun. Without gravity, the Earth would not be able to maintain its orbit and would instead move off into space in a straight line.
49.
The _____ of an object
consists of its speed and direction.
Correct Answer
A. Velocity
Explanation
The correct answer is velocity. Velocity is a vector quantity that includes both the speed and direction of an object. Speed only refers to how fast an object is moving, while velocity takes into account the direction in which the object is moving. Therefore, velocity is the appropriate term to describe the combination of speed and direction.
50.
If the man is pulling with a force of 100 Newtons to the left and the elephant made of elements is pulling with a force of 1000 Newtons to the right then what is the net force?
Correct Answer
D. 900 N right
Explanation
The net force can be calculated by subtracting the force pulling to the left from the force pulling to the right. In this case, the man is pulling with a force of 100 Newtons to the left, and the elephant made of elements is pulling with a force of 1000 Newtons to the right. Therefore, the net force is 1000 N - 100 N = 900 N to the right.