p2.2 - newton's laws

what 3 things happen in an interaction pair

each force acts on a different object

the forces act in opposite directions

the forces have the same mangitude and type (e.g. gravitational)

what is newton’s third law

for every action there is an equal and opposite reaction

what are 4 examples of contact forces

friction

drag

upthrust

tension

what is newton’s first law

an object will continue to stay at rest or move with uniform velocity unless a force acts on it

(the principle of intertia)

what is inertia

a measure of how difficult it is to change the velocity of an object

what can a resultant force do

change the speed and/or direction of an object

what is newton’s second law

the acceleration that the resultant force produces on an object depends on the size of the resultant force and the mass of the object

why does an object move in a circle

if there’s a force acting on it directed to the centre of the circle

what is terminal velocity

the constant speed that a freely falling object reaches when drag equals weight

what 2 things does momentum depend on

mass and velocity

what is the law of conservation of momentum

the total momentum before an event is equal to the total momentum after an event

what is an elastic collision

a collision in which no energy is transfered to other stores (remains only as kinetic energy)

what is doing work

using a force to transfer energy between stores