Work and Energy - Section 4.2 Quiz

When a force causes an object to move a distance in the same direction as the force, then work equals
1. force x distance.
2. energy x force.
3. potential energy/kinetic energy.
4. distance x work.
In which example is work not being done?
1. A gale-force wind whips against a stone garden wall
2. A pot of water begins to boil
3. A startled deer bolts off into the brush
4. A child takes her dolls for a ride in a stroller
Which statement about energy is true?
1. Energy is the ability to apply a force and move an object
2. Energy equals the work done on an object multiplied by the force applied to it
3. When an object moves, energy is transformed into matter
4. When an object moves, kinetic energy is transformed into potential energy
What is the best example of gravitational potential energy?
1. A Frisbee flying disc is lodged in a tree's canopy
2. An electric train moving on tracks at high speed
3. The molecules in a piece of wood bumping into each other
4. A fully charged battery in a remote control unit
What would have the most kinetic energy?
1. A skydiver hurtling toward the ground before opening their parachute
2. A Frisbee flying disc lodged in a tree's canopy
3. A frog sitting on a lily pad
4. A fully charged battery in a remote control unit
Which object would be closest to having no kinetic energy?
1. A chunk of ice floating in space, which is close to absolute zero degrees
2. An astronaut floating in the International Space Station
3. A piece of core material from the center of the Earth
4. A bucket chair poised motionless at the top of a Ferris wheel as people get on the ride
When you do work by lifting a backpack over your shoulder, the backpack gains potential energy in the form of gravitational potential energy. Energy cannot be created or destroyed so where did this extra energy come from?
1. The chemical energy in your muscles
2. The kinetic energy of the backpack
3. The gravitational potential energy of the Earth itself
4. Energy lost in the friction with air particles as the backpack was lifted
When friction acts on an object, kinetic energy is transformed into thermal energy. Friction is therefore a type of
1. force.
2. work.
3. potential energy.
4. kinetic energy.
Work is expressed in units called joules, which are
1. newtons x metres.
2. newtons/metres.
3. kilograms x N/kg.
4. kilograms x newtons.
A ballroom dancer lifts his partner in a move called a dance lift.

How much work does he do by lifting this 45 kg woman 1metre in the air?
1. 441 J
2. 46 J
3. 46 N
4. 441 N