Revision Exercise two:

Forces and Motion

At terminal velocity the gravitational force down equals the air resistance force up.

vehicle stopping distance depends on the speed squared.

moment = force × perpendicular distance from pivot

weight of a body acts through its centre of gravity

principle of moments: in equalibrium clockwise moments equal anticlockwise

Hooke’s law: the force is proportional to the extension

True for the initial linear region of a force - extension graph

pressure = force / Area   unit: (P) Pascal

pressure at a point in a gas or liquid acts equally in all directions

pressure in a liquid = height × density × g

p = h× ρ × g