Forces

Question 1

What are the 2 things a force can be?

Answer 1

A push or a pull.

Question 2

How are forces measured?

Answer 2

Using a force meter.

Question 3

How does a force meter work?

Answer 3

Force meters contain a spring connected to a metal hook. The spring stretches when a force is applied to the hook. The bigger the force applied, the longer the spring stretches and the bigger the reading.

Question 4

What are forces measured in?

Answer 4

Newtons.

Question 5

What is mass?

Answer 5

The amount of matter or stuff something contains.

Question 6

What is gravity?

Answer 6

The force that attracts objects together.

Question 7

When does gravitational force increase?

Answer 7

The masses are bigger.

The objects are closer.

Question 8

What is weight?

Answer 8

A force caused by gravity.

Question 9

What is the weight of an object?

Answer 9

The gravitational force between the object and the Earth.

Question 10

What is the difference between weight and mass?

Answer 10

Weight is measured in newtons and mass is measured in kilograms or grams. Also the mass of an object stays the same wherever it is, whereas it’s weight can change.

Question 11

What do we need to know to work out pressure?

Answer 11

1. The force or weight applied.

2. The area over which the force or weight works.

Question 12

What is the equation to work out pressure?

Answer 12

pressure = force ÷ area

Question 13

How can we show forces acting on an object?

Answer 13

Using a force diagram.

Question 14

What does an arrow on a force diagram show?

Answer 14

The size of the force (the longer the arrow, the bigger the force).
The direction in which the force acts.

Question 15

What are balanced forces?

Answer 15

When two forces acting on an object are equal in size but act in opposite directions.

Question 16

What happens if the forces on an object is balanced or there are no forces acting on it?

Answer 16

An object that is not moving stays still.

An object that is moving continues to move at the same speed and in the same direction.

Question 17

What are unbalanced forces?

Answer 17

When two forces acting on an object are not equal in size.

Question 18

What happens if the forces on an abject are unbalanced?

Answer 18

An object that is not moving starts to move.

An object that is moving changes speed or direction.

Question 19

What is the size of the overall force on an object called?

Answer 19

The resultant force.

Question 20

Give some examples of helpful frictional forces.

Answer 20

Friction between our shoes and the floor stop us from slipping.
Friction between tyres and the road stop cars from skidding.
Friction between the brakes and wheel help bikes and cars slow down.

Question 21

Give some examples of unhelpful frictional forces.

Answer 21

When there is a lot of friction between moving parts, energy is lost to the surroundings as heat. Think of what happens when you rub your hands together quickly. The friction warms them up.

Question 22

What is air resistance caused by?

Answer 22

The frictional forces of the air against the vehicle. The faster the vehicle moves, the bigger the air resistance becomes. The top speed of a vehicle is reached when the force from the cyclist or engine is balanced by air resistance.

Question 23

What happens to a force if there is pivot?

Answer 23

It can make objects turn.

Question 24

What is a moment?

Answer 24

When a force is turned around a pivot.

Question 25

What do we need to know to work out a moment?

Answer 25

The distance from the pivot that the force is applied.

The size of the force applied.

Question 26

What is the equation for working out a moment?

Answer 26

moment = force × distance