Forces

Question 1

What are forces?

Answer 1

Forces are pushes and pulls that occur when objects interact.

Question 2

Can you see a force?

Answer 2

We can see the effects of the forces but not the forces themselves.

Question 3

What are contact forces?

Answer 3

Forces that only occur when objects are touching.

Question 4

What are some contact forces?

Answer 4

-Friction
-normal contact force
-air resistance
-upthrust

Question 5

What are non-contact forces?

Answer 5

Forces that can occur over a distance.

Question 6

What are some non-contact forces?

Answer 6

-weight
-magnetic
-electrostatic

Question 7

How are forces represented on diagrams?

Answer 7

Forces are represented on diagrams by using a scaled arrow.

Question 8

What does a dot represent in a free body diagram?

Answer 8

The object

Question 9

How is the object represented in a free body diagram?

Answer 9

A dot

Question 10

Which direction do the arrows point in a force diagram?

Answer 10

The arrows should point in the direction of the force

Question 11

What does it mean when forces are balanced?

Answer 11

When forces acting in opposite directions are the same size we say the forces are balanced

Question 12

What happens to a stationary object when the forces on it are balanced?

Answer 12

It remains stationary.

Question 13

What happens to a moving object when the forces on it are balanced?

Answer 13

It moves with constant speed.

Question 14

What does it mean when forces are unbalanced?

Answer 14

When forces acting in opposite directions are NOT the same size we say the forces are unbalanced

Question 15

What happens when the forces on an object are unbalanced?

Answer 15

An object can speed up, slow down or change direction.

Question 16

When will an object float?

Answer 16

If the upthrust can equal the weight.

Question 17

When will an object sink?

Answer 17

When the weight is greater than the upthrust

Question 18

If the overall density of an object is greater than that of the liquid it will _____

Answer 18

sink

Question 19

How can you change if an object floats or sinks?

Answer 19

Changing the shape of the object (to include air) or the temperature/density of the liquid.

Question 20

What else can you call air and water resistance?

Answer 20

Drag force

Question 21

Drag force is in the ________ direction to the movement

Answer 21

Opposite

Question 22

How can you increase the drag force of an object?

Answer 22

-Larger surface area
-moving faster
-moving through a more viscous liquid

Question 23

How can you decrease the drag force of an object?

Answer 23

streamline the object

Question 24

How does a parachute work?

Answer 24

A parachutist will accelerate towards the ground when their weight is bigger than air resistance (unbalanced). When air resistance is the same size as weight it will move at a constant speed (balanced). Opening a parachute increases air resistance and it slows the parachutist down (unbalanced).

Question 25

What is mass

Answer 25

The amount of matter an object is made from.

Question 26

How do you measure mass

Answer 26

In kilograms, kg

Question 27

What is weight

Answer 27

the force when gravity is acting on a mass.

Question 28

How is weight measured?

Answer 28

In Newtons, N

Question 29

What is the word equation for weight?

Answer 29

weight = mass x gravitational field strength

Question 30

Is weight variable or constant

Answer 30

Weight varies with gravitational field strength.

Question 31

Is mass variable or constant

Answer 31

Mass will always be constant

Question 32

All objects with mass have a...

Answer 32

gravitational pull

Question 33

Objects with more mass (like planets) have a greater or lesser gravitational pull

Answer 33

greater

Question 34

Is the gravitational pull stronger nearer or further from the object?

Answer 34

Nearer (on Earth's surface rather than orbiting).

Question 35

Friction occurs when...

Answer 35

One surface moves along another

Question 36

A rough surface will cause a _______ friction force than a smooth surface.

Answer 36

larger

Question 37

Is friction the same or opposite direction to movement?

Answer 37

Opposite direction

Question 38

How can you reduce friction?

Answer 38

By using lubrication such as oil.

Question 39

How is friction useful?

Answer 39

It stops us falling over.

Question 40

How is friction unhelpful?

Answer 40

It causes surfaces to wear away and heat up

Question 41

How does a Newton meter work?

Answer 41

A pulling force like weight will stretch a spring

Question 42

Forces can change the shape of an object by...

Answer 42

Stretching (extending) or compressing (squashing)

Question 43

Ir order to get reliable results, only one _______ should be changed during an experiment

Answer 43

variable

Question 44

A spring will stretch proportionally to the force applied. This means that if the force is doubled, the length it extends...

Answer 44

doubles.