Work and PowerTime to Practice

Skyler uses 30 N of force to push a grocery cart 100 meters. How much work does she do?

Skyler uses 30 N of force to push a grocery cart 100 meters. How much work does she do?

W =Fd300 N x 100 meters = 3,000 J

Roy uses 15 N of force to push a box 15 meters across a room. How much work did he do?

Roy uses 15 N of force to push a box 15 meters across a room. How much work did he do?

W = Fd15 N x 15 m = 225 J

A 50 N child climbs a 5 meter slide. How much work is done by the child?

A 50 N child climbs a 5 meter slide. How much work is done by the child?

W = Fd50 N x 5 m = 250 J

Rylee does 45 J of work to push a felt marker 3 meters. How much force did she use?

Rylee does 45 J of work to push a

felt marker 3 meters. How much force did she use?

F = W/d

45 J / 3 m = 15 N

Sherry uses a force of 25 Newtons to lift her suitcase while doing 75 Joules of work. How far did she lift her suitcase?

Sherry uses a force of 25 Newtons to lift her suitcase while doing 75 Joules of work. How far did she lift her suitcase?

d = w/F75 J/25 N = 3 meters

A lighting fixture, with 4 bulbs, each using 500 J of electrical power burn for 20 s. What is the wattage (power) of all four light bulbs?

A lighting fixture, with 4 bulbs, each using 500 J of electrical power burn for 20 s. What is the wattage (power) of all four light bulbs?

P = w/t500 x 4 = 2000/20 s = 100 watts

If you did 100 J of work in 5 seconds, what was your power output?

If you did 100 J of work in 5 seconds, what was your power output?

P = w/t

100 J / 5 s = 20 watts

A deflated hot air balloon weighs a total of 8000 N. Filled with hot air, the balloon rises to a height of 1000 meters. How much work is accomplished by the hot air?

A deflated hot air balloon weighs a total of 8000 N. Filled with hot air, the balloon rises to a height of 1000 meters. How much work is accomplished by the hot air?

W = Fd8000 x 1000 = 8,000,000 J

Shea Weber, of the Nashville Predators, slaps a hockey puck with 2493 Joules of work when he shoots to score a goal that is 10 meters away. How much force did Shea use to hit the puck?

Shea Weber, of the Nashville Predators, slaps a hockey puck with 2493 Joules of work when he shoots to score a goal that is 10 meters away. How much force did Shea use to hit the puck?

F=W/d2493 J/10 m = 249.3 N

If it takes you 20 seconds to do

800 J of work on a box of books to move them up an inclined plane, what is your power output?

If it takes you 20 seconds to do 800 J of work on a box of books to move them up an inclined plane, what is your power output?

Power = work/time 800 J / 20 s = 40 watts