Work and Energy

A Joule is a unit of?

• Force

• Work

• Energy

• Power

Which of the following statements are true about work?

• Work is a form of energy.

• 
  Work is a time-based quantity; it is dependent upon how fast a force displaces an object.

• 
  Newton is the standard metric unit of work.

• None of these.

Which of the following statements are true about potential energy?

• Potential energy is dependent on the speed of a body.

• Moving objects cannot have potential energy.

• 
  Potential energy is the energy stored in an object due to its position.

• 
  None of these

Which of the following statements are true about kinetic energy?

• Kinetic energy is the form of mechanical energy which depends upon the position of an object.

• 
  If an object is on the ground, then it does not have any kinetic energy.

• 
  If an object is at rest, then it does not have any kinetic energy.

• 
  None of these

At which point is potential energy greatest?

• W

• X

• Y

• Z

At which point on the roller coaster is the kinetic energy at its maximum?

• A

• B

• C

• D

When a pendulum swings, at which point is potential energy at its greatest?

• 1 & 5

• 2 & 4

• 3

• Impossible to determine.

A 10-kg box is lying on a horizontal floor. It is pulled 3 m horizontally with a force of 30 N. What is the work done in Joules?

• 0

• 30

• 90

• 294

How much work must be done to stop a 1250-kg car traveling at 105 km/hr?

• 480 kJ

• 540 kJ

• 630 kJ

• 720 kJ

At an accident scene on a level road, investigators measure a car’s skid mark to be 88 m long. The accident occurred on a rainy day and the coefficient of kinetic friction was estimated to be 0.42. Use these data to determine the speed of the car when the driver slammed on (and locked) the brakes.

• 15 m/s

• 18 m/s

• 27 m/s

• 30 m/s