Work
I push a stalled car with 50N of force, it does not move. How much work is done?
no work is done!
if an object is not moving it has _____ KE
0
When an object is falling from a tree, ________ energy is converted to ______________ energy.
potential, kinetic
True or False: Energy can be destroyed.
False
The unit for power is called the
Watt.
A 900N mountain climber scales a 100m cliff. How much work is done by the mountain climber?
90,000 J
Stored energy is _______________ energy.
potential
The work done lifting an object is _____ its change in potential energy
equal to
The total energy of a system is equal to the sum of _________________ and _________________.
E= KE +PE
What is the formula to find power
p= w/T
Amy uses 20N of force to push a lawn mower 10 meters. How much work does she do?
200 J
What is the Kinetic Energy of a 150 kg object that is moving with a speed of 15 m/s?
16,875 J
What is the minimum kinetic energy required to make a 10kg roller coaster car climb a 7m hill?
KE=686 Joules
If 4500 joules of work are done to lift an object in 5 seconds, what is the power?
900 W
Angela uses a force of 25 Newtons to lift her grocery bag while doing 50 Joules of work. How far did she lift the grocery bags?
2 m
A jar of pasta sauce is sitting on a shelf in the kitchen. The jar weighs 0.25 kg and is sitting 3.5m above the ground.
8.75 Joules
How much potential energy does a 500kg water tank have if it is 10 meters above the ground.
4900 Joules
A person pushes a box across the floor a distance of 50 m Pushing the box required a force of 20 N and took the person 40 sec. a. What is the work? b. What is the power?
work= 1000 J power= 25 W
Who does more work? Person A who lifts a 30N box 4 m or person B who lifts a 50 N box 1.5 m
Person A
Former Quarterback Brett Favre throws a football at a speed of 35 meters per second. If the Kinetic energy of the pass is 245 J, what would the mass of the football be?
245 Joules
What is the total mechanical energy of a 75Kg Plane that is 20 meter high above the ground and moving and 10m/s?
18450 Joules
A 5 kg ball is at rest at a height of 10 m. How fast is the ball moving at 5 m?
10 m/s
How much time does it take for a 200 watt light bulb to use 5000J of energy?
25 seconds