work, energy and power

Question 1

what is work done

Answer 1

the energy transferred

Question 2

how is work done calculated when the force is at an angle to the motion of travel

Answer 2

resolve for the components of the force and only use the one in the same direction as the motion of travel

Question 3

what is the conservation of energy

Answer 3

energy can not be created or destroyed only transferred from one form to another

Question 4

how does the energy in a projectile change

Answer 4

it starts as kinetic energy and is transferred to GPE. at the very top its all GPE. then it starts falling again and becomes kinetic energy again

Question 5

how can you calculate the work done climbing stairs

Answer 5

the work done must equal the GPE at the top of the stairs

Question 6

how can you calculate the work done by a slingshot

Answer 6

the work done must be equal to the elastic potential energy which is converted into kinetic energy

Question 7

what is power

Answer 7

the rate of energy transfer which is the same as the rate of work done

Question 8

define efficiency

Answer 8

the fraction or percentage of the total energy that is converted to useful energy