# Final: Work and Energy Flashcards

which of the following processes require the most work?

a person lifts a 1 kg weight 1 m off the floor

a man pushes a crate along a factory floor by exerting a force of 55N. If the crate moves a distance of 4 m, how much work does the man perform?

220 N

what are the units of power

watts, horsepower, joules per second (all of the above)

which is not a simple machine?

a pair of scissors

which is an example of a wheel and an axle

a screwdriver

which is not in the inclined plane family

a wheel and axle

which statement about work and energy is not true

work and energy are always equal

a medicine ball has a mass of 5 kg and is thrown with a speed of 2 m/s. what is its kinetic energy?

500 J

the kind of energy associated with atomic bonds is

chemical energy

a pendulum is swinging back and forth and has a kinetic energy of 400 J at a particular point in its path. Which statement is not true?

both the kinetic and potential energy are decreasing

the brakes on a car exert a force of 6000 N in getting the car to stop. If the work done by the brakes is 120000 N in coming to a stop, how many meters did the car travel after the driver applied the brakes?

20 m

an object has a kinetic energy of 810 J after falling a certain distance. if the mass of the object is 20 kg, what is the speed of the object at this time?

9 m/s

a quantity that measures the effects of a force acting over a distance is called

work

a quantity that measures how much a machine multiplies force or distance is called

mechanical advantage

all levers have a rigid arm that turns around a point called the

fulcrum