mechanics

Question 1

scalars

Answer 1

distance
speed
mass
temperature

Question 2

vectors

Answer 2

displacement
force
velocity
acceleration

Question 3

newtons first law

Answer 3

an object in motion will remain at constant velocity unless acted upon by a resultant force

Question 4

newtons second law

Answer 4

acceleration of an object is proportional to the resultant force it experiences, F=ma

Question 5

terminal velocity during free fall

Answer 5

initially the object accelerates with the resultant force of gravity, but as velocity increases the air resistance will also increase. this means that the rate of acceleration is decreasing until acceleration is zero and terminal velocity is reached

Question 6

newtons third law

Answer 6

every action has an equal and opposite reaction. the forces must be on different objects. The same type of force, of the same magnitude in opposite directions

Question 7

principle of conservation of linear momentum

Answer 7

momentum is always conserved in a closed system, where no external forces act, momentum before=momentum after

Question 8

force and momentum

Answer 8

due to newtons second law, F=m, and acceleration being change in velocity over change in time, force is the rate of change of momentum

Question 9

moments

Answer 9

force multiplied by a perpendicular distance from the line of action of the force to the point.
sum of clockwise=sum of anticlockwise

Question 10

uniform object

Answer 10

gravity acts at the centre of the object. object does not bend

Question 11

work

Answer 11

force causing a motion multiplied by the distance travelled in the direction of the motion

Question 12

principle of conservation of energy

Answer 12

it cannot be created or destroyed.
energy in=energy out