1.
_____ is a system of objects that are not moving with respect to one another.
Correct Answer
B. A frame of reference
Explanation
A frame of reference is a system of objects that are not moving with respect to one another. It provides a stationary point from which motion can be observed and measured. By using a frame of reference, we can determine the position, velocity, and acceleration of objects in motion relative to the chosen reference point. This allows us to analyze and describe the motion of objects accurately.
2.
A man is moving 2 m/s. The train he is on is moving at 90 m/s. What is the man's relative motion to someone watching the train go by?
Correct Answer
A. 92 m/s
Explanation
The man's relative motion to someone watching the train go by would be the sum of his velocity and the velocity of the train. Since the man is moving at 2 m/s and the train is moving at 90 m/s, their velocities would add up to give a relative motion of 92 m/s.
3.
The speed of a flight attendant walking down the aisle of a moving plane is NOT the same in relation to ________.
Correct Answer
B. A person on the ground
Explanation
The speed of a flight attendant walking down the aisle of a moving plane is NOT the same in relation to a person on the ground because the plane is moving forward while the flight attendant is also moving forward. Therefore, the flight attendant's speed in relation to a person on the ground would be the sum of their individual speeds.
4.
Displacement is distance combined with ________.
Correct Answer
C. Direction
Explanation
Displacement is a vector quantity that not only includes the distance traveled but also the direction in which an object has moved. In other words, it describes the change in position from the initial point to the final point, taking into account both the magnitude and the direction of the movement. Therefore, the correct answer is "direction".
5.
Which of the following measurements is a displacement?
Correct Answer
A. 19 km, South
Explanation
Displacement refers to the change in position of an object from its initial point to its final point, taking into account both the distance and direction. In this case, "19 km, South" is a displacement because it specifies a distance of 19 km in the south direction, indicating a change in position from the initial point to the final point. The other options do not provide information about a change in position or direction, making them not displacements.
6.
The SI unit for distance is the ________.
Correct Answer
D. Meter
Explanation
The SI unit for distance is the meter. The meter is the fundamental unit of length in the International System of Units (SI). It is defined as the length of the path traveled by light in a vacuum during a specific time interval. The meter is commonly used to measure distances on Earth and is a standard unit in various fields such as physics, engineering, and everyday measurements.
7.
The SI unit for measuring time is the ____.
Correct Answer
C. Seconds
Explanation
The SI unit for measuring time is seconds. This is because seconds are a standard unit of measurement for time in the International System of Units (SI). It is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom.
8.
Displacement vectors of 3 m and 5 m in the same direction combine to make a displacement vector that is ________.
Correct Answer
C. 8 m
Explanation
When two displacement vectors are in the same direction, their magnitudes can be added to find the resultant displacement. In this case, the displacement vectors are 3 m and 5 m. Adding these two magnitudes, we get 3 + 5 = 8 m. Therefore, the displacement vector that is formed by combining these two vectors is 8 m.
9.
A delivery truck driver's round trip route from the warehouse takes her 3 km East, then 1 km North, then 3 km West, and then 1 km South. Which of the following statements is FALSE?(HINT: You'll have to find both distance and displacement to answer the question)
Correct Answer
C. After driving 3 km east and 1 km north, the magnitude of the distance and displacement are the same.
Explanation
After driving 3 km east and 1 km north, the magnitude of the distance and displacement are not the same. The distance traveled is the sum of the individual distances traveled in each direction, which is 3 km + 1 km = 4 km. However, the displacement is the straight-line distance from the starting point to the final point, which can be found using Pythagoras' theorem as sqrt((3 km)^2 + (1 km)^2) = sqrt(10) km. Therefore, the magnitude of the distance and displacement are different in this case.
10.
A man drives 3 km east from home to the store and then 2 km west to a friends house. What is his distance from the starting point, at home?
Correct Answer
D. 5 km
Explanation
The man initially drives 3 km east from home to the store, so he is 3 km away from home. Then, he drives 2 km west to his friend's house, which means he moves 2 km in the opposite direction. Therefore, the man's total displacement from the starting point is 3 km - 2 km = 1 km east. Thus, his distance from the starting point, at home, is 1 km.
11.
Speed is described in units of ______.
Correct Answer
D. Distance and time
Explanation
Speed is a measure of how quickly an object moves over a certain distance in a given amount of time. Therefore, speed is described in units of distance and time. The distance is typically measured in meters or kilometers, while the time is measured in seconds or hours.
12.
If you jog for 1 hour and travel 10 km, 10 km/h describes your _____.
Correct Answer
A. Average speed
Explanation
The correct answer is average speed because it represents the total distance traveled divided by the total time taken. In this case, jogging for 1 hour and traveling 10 km gives an average speed of 10 km/h. Velocity refers to the speed in a given direction, displacement is the change in position, and acceleration is the rate of change of velocity.
13.
When you look at a speedometer in a moving car, you can see the car's _______.
Correct Answer
B. Instantaneous speed
Explanation
When you look at a speedometer in a moving car, you can see the car's instantaneous speed. The speedometer provides the current speed of the car at any given moment. It gives a real-time measurement of the car's velocity, which is the rate at which the car is changing its position. The instantaneous speed is different from average speed, which is the total distance traveled divided by the total time taken. Similarly, instantaneous acceleration refers to the rate at which the car's velocity is changing at a specific point in time.
14.
Speed in a certain direction is called ______.
Correct Answer
A. Velocity
Explanation
Velocity is the correct answer because it refers to the speed of an object in a specific direction. Unlike speed, which only measures how fast an object is moving, velocity takes into account both the magnitude and direction of the object's motion. Therefore, velocity is the appropriate term to describe speed in a certain direction.
15.
Which of the following represents the greatest speed?(HINT: convert the distances to be the same unit)
Correct Answer
A. 0.2 km/s
Explanation
The given options represent different units of speed: km/s, m/s, cm/s, and mm/s. To compare them, we need to convert them to the same unit. Since 1 km = 1000 m and 1 m = 100 cm, we can convert 0.2 km/s to m/s by multiplying it by 1000, resulting in 200 m/s. Therefore, the greatest speed among the options is 200 m/s.
16.
Which of the following is the correct SI unit of speed?
Correct Answer
B. M/s
Explanation
The correct SI unit of speed is meters per second (m/s). Speed is defined as the distance traveled per unit of time, and the SI unit for distance is meters (m) and for time is seconds (s). Therefore, combining these units gives us meters per second (m/s) as the correct SI unit for speed.
17.
If the average speed of the sea gull in a given time interval is 0 m/s, what can you say about the position of the sea gull at the end of the time interval?
Correct Answer
B. The distance traveled is zero meters
Explanation
The given answer states that the distance traveled is zero meters. This means that the sea gull has not moved from its starting position at the end of the time interval. Since the average speed is 0 m/s, it indicates that the sea gull did not change its position during the given time interval.
18.
Which of the following do you calculate when you divide the total distance traveled by the total time?
Correct Answer
C. Average speed
Explanation
When you divide the total distance traveled by the total time, you calculate the average speed. Average speed is a measure of how fast an object is moving on average over a given period of time. It is calculated by dividing the total distance traveled by the total time taken. This calculation provides an overall representation of the object's speed throughout the entire journey, regardless of any variations in speed that may have occurred during different parts of the trip.
19.
Refer to the data table. What is Sally's average speed?
Correct Answer
B. 2 m/s
20.
Refer to the data table. Which runner stops briefly?
Correct Answer
A. Alonzo
Explanation
Based on the information provided in the data table, the correct answer is Alonzo. This implies that Alonzo is the only runner who stops briefly, while Sally does not stop briefly.
21.
What does constant speed look like on a speed-time graph?
Correct Answer
D. A horizontal line above zero
Explanation
Constant speed on a speed-time graph is represented by a horizontal line above zero. This means that the object is moving at a consistent speed without any changes in its velocity. A horizontal line indicates that the speed of the object remains constant over time, while being above zero indicates that the object is moving forward or in a positive direction.
22.
Refer to the distance-time graph. The speed of the object was zero on the part of the graph labeled ______.
Correct Answer
D. BC
Explanation
The speed of the object was zero on the part of the graph labeled BC because the distance covered during that time interval was constant, indicating that the object was not moving. This is supported by the fact that the slope of the graph is horizontal, indicating no change in distance over time. Therefore, the object was stationary during the BC portion of the graph.
23.
Refer to the distance-time graph. The part of the graph showing that the object has reversed its direction of motion is _______.
Correct Answer
C. DE
Explanation
The part of the graph showing that the object has reversed its direction of motion is DE. This is because DE represents a change in the direction of the object's motion. Before point D, the object is moving in the positive direction, and after point E, it is moving in the negative direction. Therefore, DE indicates a reversal in the object's motion.
24.
Acceleration is defined as the ___________.
Correct Answer
A. Change in velocity divided by the time
Explanation
Acceleration is defined as the change in velocity divided by the time. This means that acceleration measures how quickly an object's velocity changes over a specific period of time. It is calculated by taking the difference between the final and initial velocities and dividing it by the time it takes for the change to occur. Acceleration can be positive or negative, indicating whether an object is speeding up or slowing down. It is a fundamental concept in physics and is often used to analyze the motion of objects.
25.
Which of the following is a proper SI unit for acceleration?
Correct Answer
D. M/s squared
Explanation
The proper SI unit for acceleration is m/s squared because acceleration is defined as the rate of change of velocity with time, and velocity is measured in meters per second (m/s). The squared term indicates that the unit is divided by time squared, representing the change in velocity over a specific time interval. Therefore, m/s squared is the correct unit for measuring acceleration in the International System of Units (SI).
26.
A Ferris wheel moving at a constant speed is accelerating because the _________.
Correct Answer
D. Direction is always changing
Explanation
The correct answer is "direction is always changing." A Ferris wheel moving at a constant speed is still accelerating because acceleration refers to any change in velocity, including changes in direction. Even though the speed may remain constant, the Ferris wheel is constantly changing its direction as it rotates, which means it is experiencing acceleration.
27.
Which of the following objects is NOT accelerating?
Correct Answer
D. A woman walking at 2.5 m/s along a straight line
Explanation
The woman walking at a constant speed of 2.5 m/s along a straight line is not accelerating. Acceleration is defined as a change in velocity, either in magnitude or direction. Since the woman's speed and direction remain constant, there is no change in velocity and therefore no acceleration.
28.
A ball just dropped is an example of ____________.
Correct Answer
D. Free fall with gravity
Explanation
When a ball is just dropped, it falls freely under the influence of gravity. This means that it is not being affected by any other forces, such as air resistance. The ball's motion is solely determined by the acceleration due to gravity, causing it to fall at a constant rate. Therefore, the correct answer is "free fall with gravity."
29.
The slope of a speed-time graph is equal to the __________.
Correct Answer
B. Acceleration
Explanation
The slope of a speed-time graph represents the rate of change of speed over time. In other words, it shows how quickly the speed is changing. Acceleration is defined as the rate of change of velocity over time, and since velocity is the rate of change of displacement over time, the slope of a speed-time graph can be considered as the acceleration. Therefore, the correct answer is acceleration.
30.
Refer to the distance-time and speed-time graphs. Which ball is accelerating?
Correct Answer
A. Ball A
Explanation
Based on the distance-time and speed-time graphs, we can determine acceleration by looking for a change in velocity over time. In the case of ball A, the speed-time graph shows a positive slope, indicating that the velocity is increasing. This means that ball A is accelerating. However, without further information about the other balls or the specific characteristics of the graphs, we cannot determine if any of the other balls are accelerating.
31.
Refer to the distance-time and speed-time graphs. Which ball is sitting still?
Correct Answer
B. Ball B
Explanation
Based on the information provided, the correct answer is ball B. This can be determined by looking at the speed-time graph, where the line representing ball B is flat and does not show any change in speed over time. This indicates that ball B is not moving and is sitting still.
32.
Describe the motion of the object in the following graph.
Correct Answer
D. The object is accelerating
Explanation
The graph does not show a constant speed or constant velocity because the position of the object is changing at an increasing rate. This indicates that the object is accelerating.
33.
Refer to the speed-time graph. The acceleration of the body during the first second was _________.
Correct Answer
A. 5 m/s squared
Explanation
Based on the speed-time graph, the acceleration of the body during the first second can be determined by calculating the change in velocity over the change in time. In this case, the change in velocity is 10 m/s (from 0 m/s to 10 m/s) and the change in time is 2 seconds (from 0 seconds to 2 seconds). Therefore, the acceleration is 10 m/s divided by 2 seconds, which equals 5 m/s squared.