Chapter 8 Forces In Balance

Question 1

Displacement

Answer 1

Displacement is distance without a change in direction

Question 2

Vector quantity

Answer 2

Physical quantities with size (magnitude) AND direction

Question 3

Scalar quantity

Answer 3

Physical quantities with size but NO direction

Question 4

Vector examples

Answer 4

Displacement,weight,force,velocity,acceleration

Question 5

Scalar example

Answer 5

Distance,mass,power,time,speed,energy

Question 6

Speed

Answer 6

How fast something is going(scalar quantity)

Question 7

Velocity

Answer 7

The speed in a given direction(vector quantity)

Question 8

What’s a force

Answer 8

A force is a push or pull what acts on a obejct, force is measured in Newtons(N)

Question 9

What happens when you apply a force to an object

Answer 9

Change shape by streching or pullin
Change motion by accelerating or decelerating
Change it’s state by start moving

Question 10

Whats a contact force

Answer 10

When the force is physically
touching the object

Question 11

Non contact force

Answer 11

When the force dosen’t need to touch the object to have an effect on it

Question 12

Contact force example

Answer 12

Tension,friction,air resistance,normal contact force,thrust

Question 13

Non contact force examples

Answer 13

Gravitational,magnetic,electrostatic,nuclear

Question 14

Newtons third law

Answer 14

When two objects interact with each other they exert. Equal and opposite forces on each other

Question 15

Example of newton third law

Answer 15

Person standing up(downard force-weight)
(Upaward force-normal contact force)

Question 16

Friction

Answer 16

Force exerted by a surface against an object when it moves across it

Question 17

Weight

Answer 17

The force of gravity pulling things downwards. It makes things fall, and keeps things on the ground

Question 18

Upthrust

Answer 18

t pushes things upwards when they are in a liquid. It pushes boats upward so that they do not sink

Question 19

Air resistance

Answer 19

It tries to stop things moving through the air. It pushes leaves and parachutes upwards so that they fall slowly.

Question 20

Reaction

Answer 20

It stops things from going right through solid objects. When this force acts from your chair it pushes you upwards so that you do not fall through it

Question 21

Thrust

Answer 21

A forward force, from an engine for example

Question 22

Resultant force

Answer 22

The total ammount of force acting on an object

Question 23

Balanced force

Answer 23

When the result force acting on a object is 0
Either stationary or at a constant speed

Question 24

Unbalanced force

Answer 24

When the resultant force acting on an object isn’t zero-speed will decrease on increase and direction might change

Question 25

Centre of mass

Answer 25

Is the point of an object which it’s mass can be thought of as concentrated

Question 26

How can centre of mass be found in an regular object

Answer 26

In a regular object draw lines of symmetry and where they meet is the centre of mass

Question 27

Lines of equililbrium-ireegular object

Answer 27

If card is hung from a thread,centre of mass always below in line of thread,suspend the cardattach the plumb line,then draw line along the plumb line,from a different posisiton repeat where lines cross is centre of mass

Question 28

Stability-what helps

Answer 28

Stable posisition
Low centre mass
Wide basIf
If centre of mass outside wheelbase it will tip and resultant moment is produced but if centre of mass is inside wheelbase it wont topple and resultant moment wont occur

Question 29

How to draw paralellogram forces

Answer 29

1.-find appropiate scale
2.-then draw lengths into cm from angle
3.-add two degrees at start then Subtract from 180 then measure from top arrow and bottom arrow
4.-measure from point made to original point
5.measure line in cm
6.-then change back from scale
7.-then measure angke from line