Work and Energy

Question 1

what is ‘work done’?

Answer 1

always equal to the energy transferred to or by the object

Question 2

Kinetic energy equation triangle

Answer 2

KE
0.5 x mass x Velocity^2

Question 3

define hooke’s law

Answer 3

The extension of a material is directly proportional to the force.

When a force is applied to a material that is attached at one end, or if forces are applied at both ends of the material in opposite directions, the material will EXTEND

Question 4

how to find work done from a force-extention graph

Answer 4

its the graphs area

Question 5

energy is…

Answer 5

never created or destroyed. only transefered

Question 6

what does it mean if a force is said to ‘do work’

Answer 6

the force causes an object to be displaced through a distance

Question 7

what occurs when work is done against frictional forces?

Answer 7

• a rise in temp
  (kinetic energy is converted to heat)

Question 8

explain:
the relationship between the force applied and the extension of an elastic object

Answer 8

extension is directly proportional to the force applied, provided the limit of proportionality isn’t exceeded

Question 9

what type of energy is stored in a spring when it is stretched?

Answer 9

elastic potential energy

Question 10

what type of energy is stored in a moving object

Answer 10

kinetic energy

Question 11

what happens when an object is lifted

Answer 11

its gravitational potential energy increases