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 you move, your body converts ________ energy to ______________ energy.
chemical, mechanical
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
Plants convert _____________ energy into _______________ energy.
Radiant, chemical
If the total energy is 100 J and potential energy is 25 J. What is the kinetic energy?
75 J
If 4500 joules of work are done to lift an object in 5 s, 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.
8.57 Joules
When you drive your car you convert ____________ energy in gas to ______________ energy.
Chemical, mechanical
TRUE or FALSE: The top of the largest hill on a rollercoaster has the largest amount of kinetic energy.
FALSE
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 s.
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 mass of the football is 0.4 kg, what would the kinetic energy of Brett Favre’s pass be?
245 Joules
The sun converts ________________ energy into ______________ energy and ________________ energy.
nuclear, thermal and radiant
TRUE or FALSE: The bottom of the tallest rollercoaster has the highest kinetic energy
True
Person A and Person B do the same amount of work, but Person A does it ten times slower. Who had more power?
Person B