Forces

Question 1

What is gravitational force?

Answer 1

The force of attraction between masses

Question 2

Important effects of gravitational force

Answer 2

On the surface of a planet it makes all things fall towards the floor
It gives everything weight

Question 3

Define mass

Answer 3

The amount of stuff in an object (would be given the same value everywhere in the universe)

Question 4

Define weight

Answer 4

The force acting on an object due to gravity and varies based on location
Measures in Newtons using a Newtonmeter

Question 5

What is a free body diagram?

Answer 5

Shows all the forces acting on an object

Question 6

What is resultant force?

Answer 6

The overall force acting on an point or an object

Question 7

What is work done?

Answer 7

When a resultant force moves an object

Question 8

What is one joule of work equal to?

Answer 8

Force of one newton causing an object to move the distance on meter
1J = 1Nm

Question 9

How to draw a scalar drawing

Answer 9

Draw all the forces acting on an object to scale
Then draw a straight line from the beginning of the first force to the end of the last force
Measure the length of the resultant force on the diagram to find the magnitude and the angle to find the direction of the force

Question 10

What is equilibrium

Answer 10

The forces acting on it is balanced

Question 11

What is elastically deformed?

Answer 11

It can revert back to its original shape and length after the force has been removed

Question 12

What is inelastically deformed?

Answer 12

It cannot revert back to its original shape and length after the force has been removed

Question 13

What is extension directly proportional to?

Answer 13

Force

Question 14

What is the spring constant dependant on?

Answer 14

The material
The stiffer a spring, the greater the spring constant

Question 15

What is the maximum force known as?

Answer 15

Limit of proportionality

Question 16

Investigation to the link between force and extension

Answer 16

Measure the natural length of the spring with a ruler when it is clamped to the stand
Add mass to the spring and allow it to come to rest
Repeat with different masses
Plot a force-extension graph

Question 17

What is moments?

Answer 17

The turning effect of a force

Question 18

What is the turning effect?

Answer 18

A force may cause an object to turn about a pivot

Question 19

How do levers work?

Answer 19

Increase the distance from the pivot at which the force is applied. This means less force is needed to be applied to get the same moment
Therefor they make it easier to do work

Question 20

How do gears work?

Answer 20

Circular disks with teeth around the edge that interlock which causes the other to turn in the opposite direction
Transmit the rotational effect of a force from one place to another
a larger gear will turn slower than a smaller one

Question 21

What is the pressure of a fluid?

Answer 21

The force exerted normal to any surface in contact with a fluid

Question 22

What does pressure depend on

Answer 22

Depth and density

Question 23

What does a greater density mean (in terms of pressure)?

Answer 23

More particles able to collide which increases the pressure

Question 24

What is fluid pressure?

Answer 24

When an object is submerged in a fluid the pressure of the fluid exerts a force on it in every direction meaning it can float or sink

Question 25

What is fluid upthrust equal to?

Answer 25

The weight of the fluid that has been displaced by the object

Question 26

If the fluid upthrust is equal to the weight what happens?

Answer 26

Floats

Question 27

If the fluid upthrust is more than the weight what happens?

Answer 27

Sinks

Question 28

What does atmospheric pressure decrease with

Answer 28

Height (up away from the earths surface) as there is fewer air molecules to collide with the surface

Question 29

What is atmospheric pressure created by?

Answer 29

Air molecules colliding with the surface of the earth

Question 30

What is friction?

Answer 30

A force acting in the opposite direction to the movement which slows down the object Occurs between two surfaces in contact or when an object moves through a fluid (drag)

Question 31

What is drag?

Answer 31

The resistance on a fluid (gas or a liquid)

Question 32

Factors reducing drag

Answer 32

Keeping an object streamlined as it allows it to move through a fluid more easily

Question 33

What do frictional forces increase with?

Answer 33

Speed

Question 34

What is terminal velocity?

Answer 34

When friction builds up as speed increases, until the frictional forces are equal to the accelerating force (so the resultant force is 0) It has reaches a maximum speed/terminal velocity and fall at a steady speed

Question 35

What is terminal velocity dependant on?

Answer 35

Air resistance causes things to fall at different speeds so the terminal velocity is dependant on the drag in comparison to the weight

Question 36

What is stopping distance?

Answer 36

Thinking distance + Braking distance

Question 37

Factors affecting stopping distance

Answer 37

Thinking distance - The speed, reaction time Braking distance- speed, weather conditions, road conditions, condition of tyres, brake condition

Question 38

How do brakes work?

Answer 38

When the break pad is pushed, it causes break pads to be pressed onto the wheels, which causes friction on the wheels

Question 39

What is momentum?

Answer 39

Mass x velocity (oomph and object has)

Question 40

What is conservation of momentum?

Answer 40

The total momentum is the same after an event

Question 41

Explain how force causes change in momentum

Answer 41

When a non-zero force acts on a moving object cause velocity to change meaning there is a change in momentum (momentum = mass x velocity)

Question 42

Safety features in cars to prevent impacts of momentum

Answer 42

Crumple zones, seat belts stretch,air bags