Chapter 5: Exploring Contact and Non-Contact Forces

Question 1

Everything that has mass has gravitational pull.

Is it True/False?

Answer 1

False

Question 2

Gravity still works when there are objects in between

Is it True/False?

Answer 2

True

Question 3

Gravity stops working when there are objects in between.

Is it True/False?

Answer 3

False

Question 4

Gravity weakens with distance.

Is it True/False?

Answer 4

True

Question 5

Gravity weakens with speed.

Is it True/False?

Answer 5

False

Question 6

Mass and Gravity are the same thing. They both involve gravity.

Is it True/False?

Answer 6

False

Question 7

There is a difference between mass and weight. Mass involves gravity.

Is it True/False?

Answer 7

True

Question 8

When gravity is the only force, all objects have the same acceleration.

Is it True/False?

Answer 8

False

Question 9

What is the “mass”?

Answer 9

The mass of an object is the amount of matter or “stuff” it contains. The more matter of an object contains, the greater its mass.

Question 10

What is the “weight”?

Answer 10

The weight of an object is the gravitational force between the object and the Earth. The weight of an object depends upon its mass and the gravitational field strength.

Question 11

What is the calculation that combines Mass, Weight and Gravitational Field Strength?

Answer 11

Weight (N) = Mass (kg) multiply Gravitational Field Strength (N/kg)

Question 12

What is acceleration caused by?

Answer 12

Acceleration is due to gravity

Question 13

When we drop something, what causes things to fall?

Answer 13

When we drop something, the thing that causes things to fall is gravity.

Question 14

What affects everything in the same way?

Answer 14

Gravity affects everything in the same way.

Question 15

What happens when gravity effects everything to fall in the same way?

Answer 15

Gravity affects everything in the same way - causing it to accelerate towards earth at the same speed.

Question 16

When things fall more slowly, what are they being affected by?

Answer 16

When things fall more slowly, they are affected by air resistance.

Question 17

What is “air resistance”?

Answer 17

Air resistance is a force which acts in the opposite direction to gravity.

Question 18

What affects how slowly or quickly the object will fall?

Answer 18

The surface area affects how slowly or quickly and object falls.

Items with a larger surface area will fall more slowly.
Items with a smaller surface area will fall more quickly.

Question 19

Why don’t camels sink in the sand?

Answer 19

Camels don’t sink in the sand because they spread the force along their feet. This scenario will result in lower pressure because it spreads the force to its whole feet. It’s helpful in this scenario as it will prevent the camels from sinking.

Question 20

Why do rugby/football boots have spikes on them?

Answer 20

Rugby/football boots have spikes on them so that they can have a grip on the ground to prevent the footballers/rugby players from tripping. This scenario will result in higher pressure as there’s less surface area.

Question 21

What are narrow tyres better on a snow-covered road than wide tyres?

Answer 21

Narrow tyres are better on a snow-covered road than wide tyres because the smaller are has a higher pressure so it cuts through the snow and can grip the tarmac below.

Question 22

Why do tractors have wide tyres?

Answer 22

Tyres have very wide tyres because the weight is spread over a wider area and the pressure is reduced.

Question 23

Why is it easier to hammer a sharp nail into wood than a blunt one?

Answer 23

It is easier to hammer a sharp nail into wood than a blunt one because the pressure is greater through a sharp point than through a blunt one.

Question 24

Why would trying to walk across a frozen pond be even more dangerous than sliding across in a sitting position?

Answer 24

Trying to walk across a frozen pond would be even more dangerous than sliding across in a sitting position because when you sit your weight is spread through a wider area and the pressure is reduced.

Question 25

If the ice on a frozen pond was just holding your weight than when standing still, why would starting to walk cause you to fall through

Answer 25

If the ice on a frozen pond was just holding your weight than when standing still, starting to walk could cause you to fall through because when you lift one foot to step forwards all your weight is acting through one foot and so the pressure is doubled.

Question 26

What is the equation for pressure?

Answer 26

Pressure = N (force) divided by M squared (area) | The units are N/m2 or Pa ( 1N/m2 = 1Pa )

Question 27

What is up thrust?

Answer 27

Up thrust is the force which comes from the displaced water. It is equal to the weight of the water displaced.

Question 28

What is static electricity?

Answer 28

Static electricity is when an object gains or loses electric charge in the form of electrons. Objects that lose electricity electrons become positively charged. Objects that gain electrons become negatively charged.

Question 29

The three magnetic elements are iron, nickel and copper. True/False

Answer 29

False The three magnetic elements are nickel, iron and cobalt.

Question 30

The Earth’s core contains materials that are rich in iron. True/False

Answer 30

True

Question 31

Lightning occurs when a small charge escapes quickly from clouds that have become charged during a storm. True/False

Answer 31

False Lightning occurs when a large charge escapes quickly from clouds that have become charged during a storm.

Question 32

The nucleus has a positive charge because it contains positively charged protons. True/False

Answer 32

True

Question 33

An electrostatic field exists around a charged object that can exert a contact force. True/False

Answer 33

False An electrostatic field exists around a charged object that can exert a non-contact force

Question 34

Paint spraying can be improved by using spray guns that give a positive charge to the the paint. True/False

Answer 34

True

Question 35

The stronger the gravity is, the greater the weight is of an object. True/False

Answer 35

True

Question 36

When a person lies down, they can feel comfortable even on a hard surface. True/False

Answer 36

True

Question 37

If the force of a weight is acting over a small surface area, the pressure is greater. True/False

Answer 37

True

Question 38

Force is measured in Newtons. | True/False

Answer 38

True

Question 39

Pressure is a non-contact force. | True/False

Answer 39

True

Question 40

Pressure is measured in newtons. | True/False

Answer 40

False Force is measured in Newtons.

Question 41

The formula for pressure is force divided by area. | True/False

Answer 41

True

Question 42

Pressure increases as the area increases. | True/False

Answer 42

False Pressure decrease as the area increases.

Question 43

Magnetism is a contact force. | True/False

Answer 43

True

Question 44

North to North attracts, South to South attracts and North to South repels True/False

Answer 44

False North to North repels; South to South repels; North to South attracts.

Question 45

Static energy: When an object loses/gains electrons. | True/False

Answer 45

True

Question 46

Pressure increases in water when the depth increases. | True/False

Answer 46

True

Question 47

The higher you go in atmosphere the more pressure | True/False

Answer 47

False The higher you go in atmosphere, the less pressure.

Question 48

The up thrust is less than the pressure, the object floats. | True/False

Answer 48

False The weight is less than the pressure, the object floats.