Physics (Energy and Power)

Question 1

Momentum

Answer 1

p (momentum)= mass • velocity

m increases p increases
v increases p increases

Question 2

Gravitational Potential Energy

Answer 2

GPE= mgh

GPE vs Height graph.
-> linear increase.

Question 3

Spring Potential Energy

Answer 3

SPE= 1/2kx²

• > k= spring constant (how hard to stretch a spring).
• > x= distance stretched

SPE vs distance stretched graph.
-> Parabola increase.

Question 4

Kinetic Energy

Answer 4

1/2mv²

KE vs velocity graph
-> parabola increase.

Question 5

Energy

Answer 5

Conservation of energy—> energy cannot be or destroyed.
-> KEi + PEi = KEf + PEf

Conservative forces: we can keep track of energy.

Non conservative forces: Friction, Resistance in a wire and air resistance, drag in a fluid.
-> KEi + PEi = KEf + PEf + work

Question 6

Work

Answer 6

Moving energy in (or out of a system) e.g KE, GPE

Work= Fdcos θ

Pressure• ΔVolume = work

Question 7

Mechanical Advantage and Efficiency

Answer 7

Mechanical Advantage = Force out/Force In

Pressure* ΔV=work

Isobaric= constant pressure (there is work)
Isochoric = constant volume (no work done)

Question 8

Hydraulics

Answer 8

F1/A1=F2/A2

Area under Pressure-Volume curve also a way to find work.

Question 9

Power

Answer 9

Rate of energy being transferred.

Power: work/time
J/s= watts

Power can also be: P= F*V