Work and Energy
Energy Buckets
Work and Power
Work--> Kinetic Energy
Work & Potential Energy
100
Define: Work
the change in energy of an object done by applying a Force to an object causing it to have displacement
100

What is an example when an object has Elastic potential energy and gravitational potential energy

a car is on top of a hill and loaded on a squished spring

100

What are the SI units for power?

Watts
100
What is Kinetic Energy?
Energy of a moving object
100

How does and object obtain potential energy?

work done against a conservative force

200
What is the formula for work?
W=F(D) D=Displacement; meters F+Force; Newtons F and D must be on the same plane=work
200

A ball falling through the air

gravitational potential energy and kinetic energy

200
What is the difference between energy and power?
work and energy don't involve time, but power does
200
What is the formula for KE?
KE=1/2MV^2 (Joules)
200
Define gravitational potential energy?
Energy of an object placed at a height above a reference level
300
in which direction does friction act? ( in regards to displacement)
Opposite direction of motion; the work of friction is always negative
300

A pin ball being pushed into action by a spring. 

elastic and kinetic (maybe gravitational too!)

300

What is the formula for power

P=W/T

300
Can KE ever be negative?
No, the velocity is squared-->always positive
300
What is the formula for gravitational potential energy?
PE=mgdeltaH
400

What is an example of when force is applied by no work is done? 

push on wall or other 

400

If an 80kg object has 2300 J of kinetic energy at one position and then later goes up a 2m hill and is stopped by the spring.  How much energy is there in the squished spring? 

700 J

400
Who does more work? Spencer walking up the 20 m high staircase carrying his backpack in 10 seconds, or John running up the same staircase carrying a backpack in 3 seconds?
Same height, so same work John feels more tired because used more power
400
If an 10kg object is launched from the top of a 5kg ramp with a spring that has 400J of energy, how much KE does the object have at the bottom of the ramp? 

900J

400
A 80cm vertical spring is compressed 60cm and launches a ball 1.4m into the air.  What is the value used for x in 1/2kx2?

.6m

500
1) How much work is done if I pushed a 100 N crate across the floor with a force of 50 N for a distance of 10 M? 2) How much work is done if Ethan pushes a force of 600 against the wall for 30 seconds?
1) W=F(D) 50N(10M)=500 J 2) NO WORK BECAUSE NOT SAME AXIS
500

If an object originally has 500J of Gravitational Potential Energy and 300J of Elastic Potential Energy and later has 600J of Kinetic Energy and 80J of Gravitational Potential Energy how much energy was "lost"?  Where did it go? 

120J lost to heat 

500
a 60 kg runner runs up a flight of stairs in 10 seconds. The vertical height of the stairs in 15 m. How much power and energy is this?
Power: P=F(D)/T= 600N(15M)/10 S=900 Watts Energy: W=F(D)=600N(15M)=9,000 Joules
500
What happens if you double velocity and triple the mass?
Proportional reasoning-KE=1/2MV^2=3M(4V)=12KE
500
A 45 kg skier starts off from rest at the top of the hill 85 m high. How much PEG does the skier have at the top?
PE=mgh =60Kg(10m/s^2)(10m)
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