Definitions

Question 1

Coefficient of restitution-

Answer 1

The fraction of speed the ground gives back 0

Question 2

Momentum

Answer 2

mass x velocity

Question 3

Impulse

Answer 3

Measure of whack, A body’s change in momentum

Question 4

Scalar quantity

Answer 4

Has no direction

Question 5

Vector quantity

Answer 5

has a direction

Question 6

Angle of deflection

Answer 6

Angle between line particle would have travelled and the line the particle actually travelled

Question 7

Tonne

Answer 7

1000kg

Question 8

Kilo Watt

Answer 8

1000W

Question 9

Uniform speed

Answer 9

no acceleration

Question 10

Power

Answer 10

rate at which work is one

Question 11

Work done

Answer 11

Force in direction of motion x distance travelled

Question 12

M cubed of water

Answer 12

1000l or 1 tonne mass

Question 13

Energy

Answer 13

the capacity of a body to do work

Question 14

Potential energy

Answer 14

Energy a body has due to its position

Question 15

Kinetic energy

Answer 15

Energy a body has due to its motion

Question 16

Principle of Conservation of energy

Answer 16

The total energy of an isolated system remains constant. Energy can neither be created nor destroyed only transformed or transferred from one form to another.Force- causes objects to move

Question 17

Mass

Answer 17

it’s quantity of matter

Question 18

Newton’s first law

Answer 18

Body will continue in a state of rest or uniform motion unless it is compelled to change that state by an external force applied to it

Question 19

Newton’s second law

Answer 19

The change in momentum per unit time is proportional to the applied force and takes place along the straight line in which the force acts

Question 20

Newton’s third law

Answer 20

To every action there is an equal and opposite reaction

Question 21

Normal reaction force

Answer 21

Perpendicular to the surface of contact

Question 22

Tension

Answer 22

Force on objects by strings

Question 23

Friction

Answer 23

Force that opposes motion

Question 24

Limiting friction

Answer 24

Only a certain amount of friction can be called into play before object moves- this is called the limiting friction

Question 25

Coefficient of friction

Answer 25

Ratio of limiting friction tot he normal reaction force is a constant

Question 26

Light pulley

Answer 26

Pulley of negligible mass (0)

Question 27

Centre of gravity

Answer 27

Point through which the resultant gravitational force acts no matter what position the object is in

Question 28

Centroid

Answer 28

Centre of gravity of triangle, Where medians meet

Question 29

Median

Answer 29

Line from a triangle vertex to the midpoint of the opposite side

Question 30

Principle of moments

Answer 30

Sum of moments of forces about an axis + the moment of their sum (resultant) of the forces about that axis

Question 31

Moment of a force

Answer 31

Product of the magnitude of the force and the perpendicular distance between its line of action and the axis(turning effect)

Question 32

Centripetal force

Answer 32

Force directed towards the centre of a circle

Question 33

Relative density

Answer 33

Ratio of density of the substance to the density of water

Question 34

Density

Answer 34

Mass per unit volume

Question 35

Couple

Answer 35

Set of two equal and opposite forces which are displaced from one another