unit 4 - forces and energy

Question 1

formula for work done

Answer 1

W = fd

Question 2

give 9 types of forms of energy

Answer 2

kinetic energy - energy due to motion

potential energy - when objected changed position, shape or state

gravitational potential energy - gravity

elastic potential energy - rubber band or spring

chemical potential energy - batteries or foods

electrical potential energy - electrons transfer energy from the battery

nuclear potential energy - when nucleus split the energy released

thermal energy - hot objects cool down and give energy to surroundings

radiated energy - sunlight or sound waves

Question 3

si unit for work donw

Answer 3

joules ( J )

Question 4

what is the law of conservation of energy

Answer 4

energy cant be made or destroyed but it can change from one form to another

Question 5

the formula for gravitational potential energy

Answer 5

mgh

Question 6

the formula for kinetic energy

Answer 6

1/2 ( mv^2)

Question 7

formula for efficiency

Answer 7

useful work done / total energy input

Question 8

formula for power

Answer 8

work done/ time taken

Question 9

si unit for power

Answer 9

Watt ( w)

Question 10

examples of renewable energy resources

Answer 10

hydroelectric energy 
tidal energy 
wind energy 
wave energy 
geothermal energy 
solar energy 
biofuel