Work and Energy
Energy
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 gravitational potential energy
ABOVE THE GROUND HEIGHT NOT 0. answers Varies
100
What are the SI units for power?
Watts
100
What is Kinetic Energy?
Energy of a moving object
100
What is potential energy.
Energy when an object is still.
200
What is the formula for work?
W=F(D) D=Distance; meters F+Force; NewtonswORK IS ONLY DONE BY A FORCE THAT MOVES IN THE DIRECTION OF THE DISPLACEMENT
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
When is work done and not done during the lift of a military press?
When the object is being lifted, not at the top when it is still. wORK IS DONE AGAINST GRAVITY
300
A pin ball being pushed into action by a spring.
mechanical 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=mgH
400
What is an example of when force is applied by no work is done?
push on wall or other NO MOVEMENT IN DIRECTION OF FORCE
400
A hydroelectric dam involves what kinds of energy.
Kinetic, mechanical, electric
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
Where is kinetic energy highest on our rollercoasters?
Towards the bottom when it is going fastest
400
An object has a mass of 250 kg. It is 20 m above the ground. What is the PE?
49000J
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 second?
1) W=F(D) 50N(10M)=500 J 2) NO WORK BECAUSE NOT MOVING
500
What is the law of conservation of energy.
Energy is never created, lost, or destroyed. Only transformed.
500
runner runs up a flight of stairs using 200J of work in 10 sec
Power: P=W/T= 20 Watts
500
What happens TO KINETIC ENERGY if you double velocity and triple the mass?
Proportional reasoning-KE=1/2MV^2=3M(4V)=12KE
500
WILLIAM
LUKE
EMILY
KANE
BLAKE
WYATT