Exam 3 Target 6 Retake Preap

1. In which situation is the net force acting on a truck zero?

A. The car increases speed and changes direction.

B. The car increases speed but does not change direction.

C. The car maintains its speed but changes direction.

D. The car maintains both its speed and direction.

When the car maintains both its speed and direction, the net force acting on the truck is zero. This means that the forces acting in opposite directions cancel each other out, resulting in a balanced force. As a result, the truck will continue to move in the same direction with the same speed, without any change in its motion.

Explanation

When the car maintains both its speed and direction, the net force acting on the truck is zero. This means that the forces acting in opposite directions cancel each other out, resulting in a balanced force. As a result, the truck will continue to move in the same direction with the same speed, without any change in its motion.

2. A large force acting on a small massed object causes

A. a small acceleration.

B. a large acceleration.

C. no acceleration

D. equilibrium.

When a large force is applied to a small massed object, it causes a large acceleration. This is because the acceleration of an object is directly proportional to the force applied to it and inversely proportional to its mass. In this case, since the mass of the object is small, the force has a greater impact on its acceleration, resulting in a large acceleration.

Explanation

When a large force is applied to a small massed object, it causes a large acceleration. This is because the acceleration of an object is directly proportional to the force applied to it and inversely proportional to its mass. In this case, since the mass of the object is small, the force has a greater impact on its acceleration, resulting in a large acceleration.

3. A student holds a 6-N block of wood from a spring balance in an express elevator that maintains constant velocity traveling between floors. A spring scale reading of 5.9 N indicates that the elevator is

A. starting an ascending trip.

B. ending an ascending trip.

C. ending a descending trip.

D. traveling between floors.

In this scenario, the student is holding a 6-N block of wood in an express elevator that is maintaining a constant velocity. The spring scale reading is 5.9 N, which is slightly less than the weight of the block. This indicates that there is a slight decrease in the apparent weight of the block, which is consistent with the elevator ending an ascending trip. As the elevator slows down at the end of the ascent, the apparent weight of the block slightly decreases due to the upward force being slightly less than the weight of the block. Therefore, the correct answer is b. ending an ascending trip.

Explanation

In this scenario, the student is holding a 6-N block of wood in an express elevator that is maintaining a constant velocity. The spring scale reading is 5.9 N, which is slightly less than the weight of the block. This indicates that there is a slight decrease in the apparent weight of the block, which is consistent with the elevator ending an ascending trip. As the elevator slows down at the end of the ascent, the apparent weight of the block slightly decreases due to the upward force being slightly less than the weight of the block. Therefore, the correct answer is b. ending an ascending trip.

4. Which statement about the acceleration of an object is correct?

The correct answer is b. The acceleration of an object is directly proportional to the net external force acting on the object and inversely proportional to the mass of the object. This means that as the net external force increases, the acceleration of the object will also increase. Additionally, as the mass of the object increases, the acceleration will decrease. This relationship is described by Newton's second law of motion, which states that the acceleration of an object is equal to the net external force divided by the mass of the object.

Explanation

The correct answer is b. The acceleration of an object is directly proportional to the net external force acting on the object and inversely proportional to the mass of the object. This means that as the net external force increases, the acceleration of the object will also increase. Additionally, as the mass of the object increases, the acceleration will decrease. This relationship is described by Newton's second law of motion, which states that the acceleration of an object is equal to the net external force divided by the mass of the object.

5. The change in the horizontal velocity of a 12-kg scooter is +0.5 m/s. What is the net horizontal force acting on it?

A. +24 N

B. +6.0 N

C. some number greater than 0 N

D. 0 N

The net horizontal force acting on the scooter can be determined using Newton's second law, which states that force is equal to mass multiplied by acceleration. In this case, the change in horizontal velocity (+0.5 m/s) can be considered as the acceleration. Therefore, the force can be calculated by multiplying the mass of the scooter (12 kg) by the change in velocity (+0.5 m/s), resulting in a positive value. Since the question asks for the net horizontal force, the answer is "some number greater than 0 N".

Explanation

The net horizontal force acting on the scooter can be determined using Newton's second law, which states that force is equal to mass multiplied by acceleration. In this case, the change in horizontal velocity (+0.5 m/s) can be considered as the acceleration. Therefore, the force can be calculated by multiplying the mass of the scooter (12 kg) by the change in velocity (+0.5 m/s), resulting in a positive value. Since the question asks for the net horizontal force, the answer is "some number greater than 0 N".