Topic 1: Forces

Question 1

A force is defined as

Answer 1

A push or a pull

Question 2

A force is represented how and why is this useful

Answer 2

And arrow
useful as it shows size and magnitude

Question 3

A force is measured in using what

Answer 3

Newtons using a newton metre

Question 4

What is gravity

Answer 4

Pulls things downward and acts toward the centre of the earth

Question 5

What is friction

Answer 5

Acts to oppose the motion of an object

Question 6

Air friction

Answer 6

Another form of friction it acts on objects as they move. through the earths atmosphere

Question 7

The forces can push or pull in any direction, what happens to the object depends on these two things

Answer 7

Size of the force
Direction of the force

Question 8

If all forces on object are balanced the object will either

Answer 8

Remain at rest/stationery
Travels at constant velocity

Question 9

Unbalanced forces cause an object to

Answer 9

Speed up, Slow down (accelerate) or change direction

Question 10

What is Mass

Answer 10

The measure of the amount of substance in an object

Question 11

Mass is measured in

Answer 11

grams or kilograms

Question 12

Mass depends on

Answer 12

The size of the atoms that make up a substance and the way the atoms are packed together

Question 13

Your mass is the same

Answer 13

everywhere

Question 14

The weight of an object is

Answer 14

The measure of the amount of gravity acting on it

Question 15

Why is ur weight diff on earth

Answer 15

Because the gravity on earth is stronger.

Question 16

Weight is measured using a

Answer 16

newton balance

Question 17

Equation for weight

Answer 17

w = m x g

Question 18

Friction is

Answer 18

A force which acts to oppose the motion of an object

Question 19

Friction occurs as a result of

Answer 19

2 surfaces rub against each other

Question 20

The rougher the surface the ____ the force of friction

Answer 20

greater

Question 21

Why is friction a nuisance

Answer 21

it converts useful energy, into waste energy (e.g. heat and sound)

Question 22

The density is defined as

Answer 22

the mass of 1cm3 of a material

Question 23

Equation for density

Answer 23

D = M/V

Question 24

The density of water is

Answer 24

1g/cm3

Question 25

When heat is applied to a solid the particles gain _______ and hence ____ more

Answer 25

kinetic energy
Vibrate more

Question 26

When solids are heated their density generally _____ as the distance between particles _______ and hence occupy a larger _______ but their mass remains ______

Answer 26

decreases
increases
volume
the same

Question 27

When a liquid evaporates the density decreases further the intermolecular spacing increases and the volume decreases

Answer 27

When a liquid evaporates the density decreases further the intermolecular spacing increases and the volume decreases

Question 28

What is the extension of a spring

Answer 28

the difference between the new length and original

Question 29

What is the relationship between the extension and the force applied and why

Answer 29

The extension is directly proportional to the force applied
Because it is a straight line through the origin

Question 30

What is equation for gradient

Answer 30

Gradient = change in y / change in x

Question 31

The constant k is known as ____ the spring constant and is equal to the gradient of the force vs extension graph

Answer 31

the spring constant

Question 32

What is the point P in the graph

Answer 32

The point P is known as the limit of proportionality

Question 33

What does Hooke’s law state

Answer 33

The extension of the spring is directly proportional to the force applied considered that the LOP is not exceeded

Question 34

If the force is applied to a spring but the spring has not been stretched beyond the limit of proportionality

Answer 34

Then it should return to its original length

Question 35

The equation for the konstant is

Answer 35

k = f/e

Question 36

What is pressured defined as

Answer 36

The force of the object divided by the area of an object in contact with a surface

Question 37

Pressure depends on what two things

Answer 37

Size of the force
Size of the contact area

Question 38

equation for pressure

Answer 38

P = F/A Pressure = force/area

Question 39

Pressure can also be measured in ___ where PA is 1N/m2

Answer 39

Pascals

Question 40

The centre of gravity is defined as

Answer 40

The point where all the weight appears to act

Question 41

The centre of mass is defined as

Answer 41

The point where all the mass seems to be concentrated

Question 42

COG for a snooker cue

Answer 42

it is thicker at one end therefore the COG is not in the middle it will be closer to the thick end

Question 43

A body topples when

Answer 43

The vertical line from the centre of gravity acts outside the base

Question 44

The word stable means

Answer 44

the object is difficult to knock over

Question 45

A object remains stable when

Answer 45

It has a wide base
A low centre of gravity

Question 46

A moment is defined as

Answer 46

the product of the force, and the perpendicular distance from the pivot

Question 47

The moment depends on what two things

Answer 47

the size of the force, the perpendicular distance from the pivot

Question 48

Moment can be calculated using

Answer 48

moment = force x distance (m = f x d)

Question 49

The principle of moments states that

Answer 49

An object is in equilibrium
When the sum of the clockwise moment equals the sum of the anticlockwise moment about the same point