forcs - workdone and engery transfer

Question 1

a) when a man is pushing a box against the floor what is created between floor and box?
b) where has the chemical energy store in the man’s muscles transfer to?

Answer 1

a)friction so temp of box increases
b) to the thermal energy store of the box

Question 2

what is work?

Answer 2

a measure of energy transfer

Question 3

work done (j) equation

Answer 3

force (N) x distance (m)
F x S

Question 4

1 newton metre of work =

Answer 4

1 joule

Question 5

what energy store does a moving object have?

Answer 5

kinetic energy store

Question 6

what happens when a car brakes?

Answer 6

brakes press against the wheel. force of friction now acts between brake and wheel. kinetic energy of car transferred to thermal energy of brakes. temp of brakes increase + at the same time, car slows down as it loses kinetic energy

Question 7

when a person walks up the stairs, what are they moving against?

Answer 7

force of gravity. force of gravity acting on a person is their weight

Question 8

what must the distance be in the line of action of?

Answer 8

force

Question 9

when weight is acting vertically down, what is only relevant?

Answer 9

vertical distance

Question 10

when a person is stood at the top of stairs, what has the person’s chemical energy store been transferred to?

Answer 10

gravitational potential energy store