Revision

Question 1

Units and Formula used to measure Energy

Answer 1

Joules (J)
Kilojoules (kJ)

energy transferred = force x distance

Question 2

Units and Formula used to measure Speed

Answer 2

Metres/Seconds (m/s)
Miles per Hour (mph)
Kilometres/Hour (km/h)

speed = distance / time

Question 3

Units and Formula used to measure Moment

Answer 3

Newton Metres (Nm)

moment = force x distance

Question 4

Units and Formula used to measure Weight (a force)

Answer 4

Newtons (N)

weight = mass x g

Question 5

Units used to measure Distance

Answer 5

Kilometres (km)

Metres (m)

Question 6

Units used to measure Time

Answer 6

Hours (h)
Minutes (m)
Seconds (s)

Question 7

Units used to measure Force

Answer 7

Newton’s (N)

Question 8

Units used to measure Area

Answer 8

Metres square (m2)

Question 9

Units used to measure Mass

Answer 9

Grams (g)

Kilograms (kg)

Question 10

What are the three states of matter?

Give two examples of each.

Answer 10

Solid, Liquid and Gas

Question 11

What does ‘physical change’ mean?

Answer 11

When a substance changes from one state to another. Eg. Water (liquid) to ice (solid)

Question 12

What is the difference between a physical change and a chemical change?

Answer 12

In a physical change there is no chemical reaction and no new substances are made.

Question 13

What does it mean to say changes of state can be reversed?

Answer 13

This means all the changes of state are reversible and can be undone by another process.

Eg. Ice to liquid, to reverse the process you freeze the liquid water to get ice again.

Question 14

What is the process called when a substance changes straight from a solid to a gas?

Answer 14

Sublimation

Question 15

What is the process called when a substance changes from a solid to a liquid?

Answer 15

Melting

Question 16

What is the process called when a substance changes from a liquid to a gas?

Answer 16

Evaporation

Question 17

What is the process called when a substance changes from a gas to a liquid?

Answer 17

Condensing

Question 18

What is the process called when a substance changes from a liquid to a solid?

Answer 18

Freezing

Question 19

What is the process called when a substance changes from a solid, mixes with a liquid to form a solution?

Answer 19

Dissolving

Question 20

When a substance changes from one state of matter to another, does its mass change?

Can you give an example.

Answer 20

No.

Eg. Ice (20g) = Water (20g) = Water Vapour (20g)

Question 21

How do the changes of state alter physical properties?

Answer 21

The particles in solids are packed together tightly compared to gases and liquids. This means that solids have a higher density than gases and liquids.

When you heat a substance, it changes from a solid to a liquid to a gas. The particles move further apart and the substance becomes less dense.

Ice is different though. When you hear ice, so it melts, the particles actually become closer together. So liquid water has a higher density than solid ice.

Question 22

What is speed a measure of?

Answer 22

It is a measure of how far you travel in a set amount of time.

Question 23

What are the 3 common units of measure?

Answer 23

Metres per second (m/s)
Miles per hour (mph or miles/h)
Kilometres per hour (km/h)

Question 24

What is the formula for speed?

Answer 24

SIDOT

Speed is Distance over Time.

Speed = distance / time

Question 25

What information do you need to know in order to work out speed?

Answer 25

You need to know the distance travelled and the time taken.

Question 26

A hooligan sheep is skateboarding down a farmers track. The sheep takes exactly 5 seconds to ,over between two femce posts. The posts are 10 metres apart. What is the sheeps speed? Write down what you know. Use the formula for speed.

Answer 26

What do I know? ``` Distance = 10m Time = 5s ``` What is the formula for speed? Speed = distance / time Speed =10 / 5 = 2 m/s

Question 27

``` What do these words mean when looking at a distance-Time graph? Slope Steeper line Flat line Downhill sections Curves Steeper curves A curve levelling off ```

Answer 27

Slope - the gradient shows that the object is moving Steeper line - means the object is moving faster Flat line - where the object has stopped Downhill sections - means the object is moving back toward the starting point Curves - means the speed is changing Steeper curves - means the object is speeding up (accelerating) A curve levelling off - means the object is slowing down (decelerating)

Question 28

What are forces?

Answer 28

Forces are pushes and pulls. Forces cannot be seen but the effects of a force can be seen. Forces usually act in pairs. Forces always act in a certain direction.

Question 29

What are Forces measured in?

Answer 29

Newton’s (N)

Question 30

What are forces in a diagram represented by?

Answer 30

Arrows

Question 31

What instrument is used to measure forces?

Answer 31

A newton metre

Question 32

Sometimes objects do not need to touch for there to be forces between them. What are these types of forces called?

Answer 32

Non-Contact Forces Fore example: gravity (an elephant will fall from the sky without touching it), magnetism (a magnet attracts a paper clip without touch it) and static electricity (the static charge o a balloon makes the hair stand up without touching it).

Question 33

What are the 5 main effects of force on an objects movement?

Answer 33

1. Speeds up or starts moving an object. Like kicking a football. 2. Slows down or stops moving an object. Like air resistance will slow something down. 3. Changes the direction of an object. Like hitting a ball with a bat. 4. Turn an object. Like turning a spanner. 5. Change the shape of an object. Like stretching and compressing, bending and twisting an object.

Question 34

What is pressure?

Answer 34

Pressure is how much force is put on a certain area.

Question 35

What is the formula for pressure?

Answer 35

Pressure = force/area A given force acting over a big area means a small pressure. A given force acting over a small area means a big pressure.

Question 36

Why is someone wearing high heels more likely to sink i to snow than the same person wearing snow shoes?

Answer 36

Snow shoes: weight I spread over a large area so pressure is low and therefore she doesn’t sink I to the snow. High heels: weight is concentrated over a small area so the pressure is high and she sinks into the snow.

Question 37

What unit of measure does pressure used?

Answer 37

Newtons per metre squared | N/m2 = 1 pascal

Question 38

True or false. At sea level, the atmosphere doesn’t weigh anything.

Answer 38

False. At sea level, there’s a lot of atmosphere (air) above you. The atmosphere weighs quite a bit, so it applies a high pressure.

Question 39

True or false. Atmospheric pressure decreases with height.

Answer 39

True. The higher you go, the lower the pressure.

Question 40

Atmospheric pressure is highest at the top of a mountain.

Answer 40

False. At the top of a mountain, there’s less atmosphere above you. The atmosphere weighs less, so the pressure it applies is lower.

Question 41

Atmospheric pressure is lower on mountains than at sea level.

Answer 41

True. At sea level, there’s a lot of atmosphere (air) above you. The atmosphere weights quite a bit, so it applies a high pressure. However, at the top of a mountain, there’s less atmosphere above you. The atmosphere weighs less, so the pressure applies is lower.

Question 42

Atmospheric pressure stays the same wherever you are.

Answer 42

False.

Question 43

True or false. The pressure in liquid increases with depth?

Answer 43

True. For liquids like water, the pressure increases with depth. The pressure at the bottom of an ocean is higher than at the top.

Question 44

True or false. Water pressure causes upthrust and makes things float.

Answer 44

True. If you put an object in water, it experiences pressure from all directions. Water pressure increases with depth so the force pushing upwards at the bottom of the object is bigger than the force pushing down at the top of the object. This causes an overall upwRds force called up thrust. A boat sinks lower i to the water until the ulthrist is equal to its weight and at this point the boat will start to float. If the upthrust is less than the objects weight, it will sink.