Energy Concepts
Where is potential energy greatest on a roller coaster?
Highest point
Formula for work
W = Fd
Slope of a work vs time graph represents…
Power
Formula for momentum
p = mv
Hooke’s Law
F = kx
As an object falls, what happens to PE and KE?
PE ↓, KE ↑
Formula for power
P = W/t
Area under a force vs distance graph represents…
Work
Which has more momentum: larger mass or smaller mass (same speed)?
Larger mass
Elastic potential energy formula
½kx²
If height doubles, what happens to gravitational PE?
Doubles
If the same work is done in MORE time, what happens to power?
Decreases
PE vs mass graph shape?
Linear
What is conserved in ALL collisions?
Momentum
If stretch doubles, what happens to energy?
4×
A ball dropped from higher height—what happens to KE at impact?
Increases
A 30 N force moves an object 2 m. Work?
60 J
If a graph gets steeper over time, what is happening to power?
Increasing
In inelastic collisions, what is NOT conserved?
Kinetic energy
A spring constant is 400 N/m and stretches 0.5 m. Force?
200 N
Why does mass NOT affect speed in free fall (ignoring air resistance)?
Because acceleration due to gravity is constant; energy conversion depends on height, not mass
If time doubles but work stays the same, how does power change?
Cut in half
Why is PE vs mass linear?
Because PE = mgh (direct proportionality to mass)
Two equal masses collide and stick together with equal speeds in opposite directions—final velocity?
0
Why does spring energy increase faster than force?
Because energy depends on x², not x