P3

Question 1

Work done to overcome friction is transferred as?

Answer 1

Energy that heats the objects, that rub together and the surroundings.

Question 2

Gravitational potential energy?

Answer 2

Energy stored in an object as of its position in Earth’s gravitational field. Whenever object moved vertically upwards gains gpe equal to work done on it by lifting force. Gpe of object depends on it weight and how far it loves vertically.

Question 3

Power?

Answer 3

Rate of transfer of energy.

Question 4

Momentum?

Answer 4

Mass x velocity

Question 5

Momentum in an explosion?

Answer 5

When two objects at rest momentum=zero. In explosion objects move apart with equal and opposite momentum. One positive and one negative, so total momentum after explosion=zero.

Question 6

Force acts on object that is able to move or is moving…?

Answer 6

Momentum changes.

Question 7

Crumple zones?

Answer 7

Designed to fold in a collision. Increases the impact time and reduces force on car and people in it.

Question 8

Work done=

Answer 8

Energy transferred

Question 9

Seat belts and airbags?

Answer 9

Spread force across chest and increase impact time. Side impacts and crumple zones give away in an impact= increase impact time.

Question 10

When is work done on an object?

Answer 10

When a force makes the object move. (When work done moving object, supplied energy is transferred to the object so the work done os equal to energy transferred).