Physics Practice Questions From Forces, Energy And Motion! Quiz

1. A wheeled cart is moving eastward at a speed of 1 meter per second when it is acted on by a 30-newton force to the north and a 30-newton force to the south. Which of the following BEST explains why the cart’s speed and direction stay the same?

The new forces are perpendicular to the main force.

The new forces are balanced.

The new forces are smaller than the main force.

The new forces are in opposite directions.

Because the forces are both equal and acting in opposite directions, they are balanced, and have no effect on the cart’s motion.

Explanation

Because the forces are both equal and acting in opposite directions, they are balanced, and have no effect on the cart’s motion.

2. Two dogs are pulling on opposite ends of a rope. The dog on the left is pulling with a force of 25 newtons. The dog on the right is pulling with a force of 60 newtons. What will be the resulting motion?

The dogs will move toward the right.

The dogs will move toward the left.

The dogs will not move.

Both dogs will move in the direction that they are pulling.

The dog on the right is pulling with a greater force of 60 newtons compared to the dog on the left with a force of 25 newtons. According to Newton's second law of motion, the acceleration of an object is directly proportional to the net force applied to it. Since the net force in this case is 60 newtons (60 - 25 = 35 newtons), the dogs will experience a net force towards the right. As a result, the dogs will move in the direction of the greater force, which is towards the right.

Explanation

The dog on the right is pulling with a greater force of 60 newtons compared to the dog on the left with a force of 25 newtons. According to Newton's second law of motion, the acceleration of an object is directly proportional to the net force applied to it. Since the net force in this case is 60 newtons (60 - 25 = 35 newtons), the dogs will experience a net force towards the right. As a result, the dogs will move in the direction of the greater force, which is towards the right.

3. The man who introduced the idea that all of the continents of the Earth were at one time
joined to make one large land mass was -

Arthur Holmes

Harry Hess

John Dalton

Alfred Wegener

Alfred Wegener is the correct answer because he was the one who introduced the idea of continental drift, which states that all the continents were once joined together in a supercontinent called Pangaea. He proposed this theory in the early 20th century based on evidence such as the fit of the continents, matching fossils, and similar rock formations found on different continents. His theory revolutionized the field of geology and laid the foundation for our current understanding of plate tectonics.

Explanation

Alfred Wegener is the correct answer because he was the one who introduced the idea of continental drift, which states that all the continents were once joined together in a supercontinent called Pangaea. He proposed this theory in the early 20th century based on evidence such as the fit of the continents, matching fossils, and similar rock formations found on different continents. His theory revolutionized the field of geology and laid the foundation for our current understanding of plate tectonics.

4. A truck carrying a box is traveling 60 kilometers per hour. Suddenly, the truck brakes to a stop. Which choice best explains what will happen to the box?

The box will slide off the back because for every action there is an equal and opposite reaction.

The box will not move because objects at rest tend to stay at rest.

The box will keep moving forward because objects in motion tend to stay in motion.

The box will gain speed because, for objects of a given mass, greater force results in a greater acceleration.

The box, once in motion, keeps going even though the truck stops.

Explanation

The box, once in motion, keeps going even though the truck stops.

5. Which of these landforms would most likely be found at a divergent boundary?

Volcanic island

Mid-ocean ridge

Fault line

Mountain

At a divergent boundary, tectonic plates move away from each other, leading to the creation of new crust. This process occurs primarily in the oceanic crust, where magma rises to the surface and forms underwater mountain ranges known as mid-ocean ridges. These ridges are characterized by volcanic activity and the formation of new oceanic crust, making them the most likely landform to be found at a divergent boundary.

Explanation

At a divergent boundary, tectonic plates move away from each other, leading to the creation of new crust. This process occurs primarily in the oceanic crust, where magma rises to the surface and forms underwater mountain ranges known as mid-ocean ridges. These ridges are characterized by volcanic activity and the formation of new oceanic crust, making them the most likely landform to be found at a divergent boundary.

6. Which of these landforms is most likely to be found at a convergent boundary?

Fault line

Mountain

Mid-ocean ridge

Rift valley

At a convergent boundary, two tectonic plates collide and are forced together. This collision causes the crust to buckle and fold, resulting in the formation of mountains. Therefore, it is most likely that mountains would be found at a convergent boundary.

Explanation

At a convergent boundary, two tectonic plates collide and are forced together. This collision causes the crust to buckle and fold, resulting in the formation of mountains. Therefore, it is most likely that mountains would be found at a convergent boundary.

7. Martin gathered a toy car, a ramp, a stopwatch, a meter stick, and a variety of weights. What is he likely testing?

How the angle of a ramp affects the speed of the car

How friction affects the speed of the car

How equal forces work on the placement of the car and the ramp

How mass affects the speed of the car

Martin is likely testing how mass affects the speed of the car. He has gathered a variety of weights, indicating that he wants to investigate how different masses impact the car's speed. The other options, such as the angle of the ramp, friction, and equal forces, are not mentioned in the question and do not align with the materials Martin has gathered.

Explanation

Martin is likely testing how mass affects the speed of the car. He has gathered a variety of weights, indicating that he wants to investigate how different masses impact the car's speed. The other options, such as the angle of the ramp, friction, and equal forces, are not mentioned in the question and do not align with the materials Martin has gathered.

8. Look at the illustrations. In the first, the truck is traveling 30 miles per hour. In the second, the truck has braked to a stop. Which of Newton’s laws of motion explains what happens next?

For every action there is an equal and opposite reaction.

Objects at rest tend to stay at rest.

Objects in motion tend to stay in motion.

For objects of a given mass, greater force results in a greater acceleration.

The correct answer is "Objects in motion tend to stay in motion." According to Newton's first law of motion, an object will continue to move at a constant velocity unless acted upon by an external force. In this case, the truck was initially in motion and then braked to a stop. Therefore, according to Newton's first law, the truck will tend to stay at rest unless another force is applied to it.

Explanation

The correct answer is "Objects in motion tend to stay in motion." According to Newton's first law of motion, an object will continue to move at a constant velocity unless acted upon by an external force. In this case, the truck was initially in motion and then braked to a stop. Therefore, according to Newton's first law, the truck will tend to stay at rest unless another force is applied to it.

9. The most recently formed crust of the Earth would be found -

Where plates moving sideways passed each other

Where one plate is going under another plate

Where two plates are pushing directly toward each other

Where two plates are moving away from each other in opposite directions

The most recently formed crust of the Earth would be found where two plates are moving away from each other in opposite directions. This is because when two plates separate, magma rises to fill the gap and solidifies to form new crust. This process is known as seafloor spreading and occurs at divergent plate boundaries, such as the Mid-Atlantic Ridge. The newly formed crust is younger than the crust found at other types of plate boundaries, making it the most recently formed.

Explanation

The most recently formed crust of the Earth would be found where two plates are moving away from each other in opposite directions. This is because when two plates separate, magma rises to fill the gap and solidifies to form new crust. This process is known as seafloor spreading and occurs at divergent plate boundaries, such as the Mid-Atlantic Ridge. The newly formed crust is younger than the crust found at other types of plate boundaries, making it the most recently formed.