Types of Energy
Energy of motion
Kinetic
Name the useful transfer in a hand held torch
Chemical to light
Equation for efficiency?
Useful/total
Push, pull or twist
Equation for speed
Speed = distance/time
Energy that a bird at a constant flying height has
GPE
What does wasted energy mean?
Energy that isn't used or isn't useful
A device that takes in 200 J and gives out 50 joules of useful energy has what efficiency?
0.25
What does balanced force mean?
The forces are equal in opposite directions
Equation for acceleration
acceleration = change in speed/time
Energy linked with particles vibrating more and more
Heat
Energy that is usually wasted
Heat
If a device uses 200 Joules but wastes 50 Joules has what efficiency?
0.75
What happens if the forces are unbalanced?
The object changes speed or direction
Units for speed
m/s
Energy form found in batteries and food
Chemical
Energy transfer in a plant
Light to chemical
If a device wastes 30 Joules and gives out 70 joules of energy, what is the efficiency/
0.70
Unit of force
Newton
units for acceleration
m/s2
Energy forms that are the two E's
Electric and Elastic
Electric to heat
Main rule for efficiency to help calculate?
Answer can never be equal to or more than 1
What are the 5 main forces?
Thrust, Air resistance, Weight, Reaction and Friction
Calculate the change in speed for a car accelerating at 5m/s2 over 20 seconds.
100m/s