Unit 8 & 9 Energy - Forces Doing Work/ Forces and their Effects

Question 1

When is energy transferred?

Answer 1

Whenever things happen

Question 2

What are the energy transfers for a light bulb?

Answer 2

Electricity transfers energy to an electric light bulb, which transfers the energy to the surrounding by light and heating.

Question 3

What is the word equation for work done?

Answer 3

Work done (J) = force (N) x distance in the direction of the force (m)

Question 4

What is the symbol equation for work done

Answer 4

E = F x d

Question 5

What is power?

Answer 5

The rate at which energy is transferred.

Question 6

What is power measured in?

Answer 6

watts (W)

Question 7

What does 1 watt equal in terms of work done?

Answer 7

1 joule per second

Question 8

If there are 2 same sized boxes lifted, what makes the person produce a different power?

Answer 8

If it is lifted in a shorter time

Question 9

What is the word equation for power?

Answer 9

Power (W) = work done (J) / time taken (s)

Question 10

What is the symbol equation for power

Answer 10

P. E / t

Question 11

What are contact forces?

Answer 11

When objects are touching and they exert a force on each other

Question 12

Give an example of a normal contact force?

Answer 12

When you stand on the floor and there is an upward force from the floor on you

Question 13

Give an example of a non-contact force

Answer 13

Upthrust and gravity on a boat

Question 14

Why does the moon stay in orbit around the earth?

Answer 14

The two bodies are attracting to eachother

Question 15

What are action-reaction forces.

Answer 15

Pairs of forces acting on different objects in opposite directions

Question 16

What is a force field?

Answer 16

The space around an object where it can affect other objects

Question 17

Why do the moon and the earth affect eachother?

Answer 17

They are within each others gravitational field

Question 18

What is magnetism and static electricity

Answer 18

Other forces that affect objects that are not in direct contact

Question 19

What is a magnet?

Answer 19

An object that attracts objects made from magnetic materials

Question 20

What materials are magnetic? (3)

Answer 20

Nickel, iron, cobalt

Question 21

What is a magnetic field?

Answer 21

The space around a magnet where it can affect other materials.

Question 22

What is an electric field (electrostatic field)

Answer 22

The area around a charged object where it can affect its surroundings.

Question 23

What is the net force?

Answer 23

The resultant force, the overall force, if it isn’t balanced, there is a net force but if the are balanced, the net force is 0

Question 24

What is a free body force diagram?

Answer 24

A diagram using arrows to show forces and a simple box to show the object

Question 25

What does a scale diagram help to show

Answer 25

Hoe different forces act when they are not in opposite directions

Question 26

How doe you draw a scale diagram for finding the resultant force?

Answer 26

Create scale (in N or kN)
Draw a line to scale and use angle to draw second line
Total angle is 360 in parallelogram so use this to work out other angle.
Calculate force by measuring diagonal from the object corner.

Question 27

How can a scale diagram be used to calculate forces acting on an object?

Answer 27

Create scale (in N or kN)
Draw base line and second line using angle and force given.
Draw rectangle from this (use base line) and work out force using scale.

Question 28

What is a moment

Answer 28

A turning force

Question 29

What does the size of the moment depend on?

Answer 29

The size of the force and where it is applied

Question 30

What makes a bigger moment?

Answer 30

A greater force and further from the pivot

Question 31

What is the distance between the force and pivot measured from?

Answer 31

It is measured normal to the direction of the force

Question 32

What is the word equation for a moment?

Answer 32

Moment (No) = force (N) x distance normal (m)

Question 33

What does it mean for 2 objects to be in equilibrium in terms of moments

Answer 33

The anti-clockwise force is equal to the clockwise force.

Question 34

What is effort?

Answer 34

The amount of force that something exerts

Question 35

What is the force that acts upwards of someone standing

Answer 35

Upwards push or normal force