Motion

Question 1

Distance

Answer 1

The length of the space between one point and another.

Question 2

Speed

Answer 2

The distance travelled per unit of time.

Question 3

Time

Answer 3

A measurable period in which events or an event occurs.

Question 4

Scalar

Answer 4

A physical quantity that has magnitude only. For example, time.

Question 5

Vector

Answer 5

A physical quantity that has both magnitude and direction.

Question 6

Displacement

Answer 6

Distance in a given direction. For example, 50 m north east. It is also the shortest distance between two points.

Question 7

Velocity

Answer 7

Speed in a given direction. For example, 100 km/h south. Velocity of an object can be calculated by dividing the displacement of an object by the time taken to undergo that displacement.

Question 8

Distance time graph

Answer 8

Shows the distance something travels over the time taken to travel that distance. It is normally drawn by plotting the distance travelled on the y-axis and the time taken for the journey on the x-axis.

Question 9

Acceleration

Answer 9

When speed changes over time.

Question 10

Force

Answer 10

Forces explain why an object moves the way it does, why things stretch, twist, tear, snap, bend, break, speed up, slow down and change shape. Pushes and pulls are types of force.

Question 11

Contact forces

Answer 11

Two objects have to be in contact for these forces to occur.

Question 12

Non contact forces

Answer 12

Forces where objects do not have to be in contact for the forces to occur.

Question 13

Interaction pair

Answer 13

Pairs of forces that occur together.

Question 14

Newton meter

Answer 14

A device used to measure forces. Also known as a spring balance.

Question 15

Force meter

Answer 15

Used to measure forces digitally.

Question 16

Balanced

Answer 16

When an object does not move because competing forces cancel each other out, we say the forces are balanced.

Question 17

Equilibrium

Answer 17

An object is in equilibrium when it is subject to balanced forces.

Question 18

Unbalanced

Answer 18

When one force on an object is stronger than another force, the forces are unbalanced. Unbalanced forces cause objects to speed up, slow down or change direction.

Question 19

Dynamic

Answer 19

When an object has balanced forces acting upon it when it is moving.

Question 20

Friction

Answer 20

A force that opposes motion when two objects are placed in contact.

Question 21

Drag forces

Answer 21

Forms of friction, such as water resistance and air resistance.

Question 22

Lubrication

Answer 22

Friction between solids can be reduced by using lubrication. Examples of lubricants include oil and wax.

Question 23

Steamlining

Answer 23

volves creating a smooth surface and an aerodynamic shape. Drag forces in wind and air can be reduced by streamlining.

Question 24

Deform

Answer 24

When forces compress or stretch objects, they deform them.

Question 25

Compress

Answer 25

When a material is compressed, the material's particles move closer together.

Question 26

Stretch

Answer 26

When a material is stretched, the material's particles move further apart.

Question 27

Reaction

Answer 27

The force applied by an object in response to another force.

Question 28

Elastic

Answer 28

Any object that is able to restore its shape after it has been extended or compressed is known as an elastic object.

Question 29

Elastic limit

Answer 29

The point at which an elastic object will not restore its shape.

Question 30

Pressure

Answer 30

A measure of the force exerted per unit area of an object.

Question 31

Gas pressure

Answer 31

As gas particles move around, they collide with other objects and with each other. This force, applied over an area, causes gas pressure. The faster the gas particles move, the more force they exert, so the greater the pressure is.

Question 32

Atmospheric pressure

Answer 32

The pressure exerted by the Earth's atmosphere. Atmospheric pressure affects weather.

Question 33

Density

Answer 33

A measure of how much matter is in the object compared to how much space it takes up. It is the ratio of mass to volume.

Question 34

Buoyancy

Answer 34

If the upthrust that results from the pressure of a liquid is large enough, it will keep an object afloat, or buoyant.

Question 35

Upthrust

Answer 35

The upward force exerted by a liquid. Pressure in liquids increases with depth, which means the bottom of something in a liquid will always feel more pressure than the sides because this point is the deepest.

Question 36

Archimedes' principle

Answer 36

States that an object placed in water will feel an upthrust equal to the weight of the water it displaced.