Mechanics

Question 1

Displacement

Answer 1

Distance in a direction

Question 2

Speed

Answer 2

Rate of change of distance with respect to time

Question 3

Velocity

Answer 3

Rate of change of displacement with respect to time

Question 4

Acceleration

Answer 4

Rate of change of velocity with respect to time

Question 5

Scalar Quantity

Answer 5

Magnitude only

Question 6

Vector Quantity

Answer 6

Magnitude and direction

Question 7

A Force

Answer 7

Causes Acceleration

Question 8

The Newton

Answer 8

force which gives 1kg an acceleration of 1m/s

Question 9

Friction

Answer 9

Is a force which opposes the relative motion between objects

Question 10

Mass

Answer 10

Is a measure of how difficult it is to accelerate that body

Question 11

Weight

Answer 11

The force of Earth’s gravity acting on an object

Question 12

Momentum

Answer 12

Is the product of mass times velocity

Question 13

Newton’s first law of motion

Answer 13

Every object will remain at rest or at a constant velocity unless and external force is applied

Question 14

Newton’s second law of motion

Answer 14

the rate of change of and objects momentum is directly proportional to the force applied and is in the same direction

Question 15

Newton’s third law of motion

Answer 15

Every action has and equal but opposite reaction

Question 16

The principle of conservation of momentum

Answer 16

The total momentum after is equal to the total momentum before, provided no external forces are applied

Question 17

Density

Answer 17

An objects mass per unit volume

Question 18

Pressure

Answer 18

Force per unit area

Question 19

Archimede’s principle

Answer 19

when an object is placed in fluid the upthrust is equal to the weight of the displaced fluid

Question 20

Law of Floatation

Answer 20

The weight of a floating object is equal to the weight of the fluid it displaces

Question 21

Boyle’s law

Answer 21

at constant temperature the volume of a fixed mass of gas is inversely proportional to the pressure.

Question 22

Conditions for equilibrium

Answer 22

Vector sum of the forces in and direction is zero, the sum of the moments about any point is zero

Question 23

The moment of a force

Answer 23

the force multiplied by the perpendicular distance between the force and the fulcrum

Question 24

Work

Answer 24

Displacement by force

Question 25

Energy

Answer 25

the ability to do work

Question 26

The principle of conservation of energy

Answer 26

Energy cannot be created nor destroyed but can only be converted from one form to another

Question 27

Kinetic energy

Answer 27

the energy a body has due to its motion

Question 28

Potential energy

Answer 28

the energy a body has due to its position in a force field

Question 29

Power /work

Answer 29

the rate at which work is done

Question 30

Power /energy

Answer 30

The rate at which energy is converted from one form to another

Question 31

Angular Velocity

Answer 31

the change in angle with respect to time

Question 32

Centripetal force

Answer 32

the force acting in towards the centre required to keep and object moving in a circle

Question 33

Centripetal acceleration

Answer 33

when moving in a circle the acceleration it has towards the centre of the circle

Question 34

Hooke's law

Answer 34

when an object is stretched the restoring force is directly proportional to the displacement

Question 35

Period of the orbit

Answer 35

the time taken for a satellite to go once around the central body