PRE UPS 2

Which of the following statements is true regarding the work done by a force on an object?

• Work is always positive

• Work is only zero if the force is zero

• Work is always negative

• Work can be positive, negative, or zero

If a car is accelerating along a straight road, what can be said about the net work done on the car?

• Net work done is zero
• Net work done is negative
• Net work done is positive
• Net work done depends on the mass of the car

Which of the following statements is correct regarding the conservation of mechanical energy in a system?

• Mechanical energy is always conserved, regardless of external forces
• Mechanical energy is only conserved in the absence of any dissipative force
• Mechanical energy is never conserved in any system
• Mechanical energy conservation is only applicable to simple machines

How is power related to the time it takes to do work?

• Power is independent of the time taken.

• Power is directly proportional to time.

• Power is inversely proportional to time.

• Power and time have no relationship.

Why is it possible for an object to have energy even when it's not in motion?

• Energy is only associated with motion.

• Energy can exist in different forms such as potential energy.

• Energy is always related to the object's mass.

• Only objects in motion possess potential energy.

What happens to the magnitude of the centripetal force if the speed of an object in circular motion is doubled?

• It becomes half.
• It remains the same.
• It becomes four times.
• It becomes double.

What role does friction play in circular motion when a car turns on a flat road?

• Friction provides the centripetal force.

• Friction has no effect on circular motion.

• Friction opposes the centripetal force.

• Friction contributes to tangential acceleration.

If the tension in a string is the only force acting on an object in circular motion, what is the direction of the force?

• Radial, pointing outward.
• Radial, pointing inward.
• Tangential to the circular path.
• Along the axis of rotation.

For a rigid body to be in equilibrium, the net _______ acting on any axis of the body must be zero.

• force

• external torque

• external force

• frictional force

What is the analogue of mass in rotational motion?

• Moment of inertia

• Momentum

• Angular momentum

• Torque