Topic 4- Forces And Energy Flashcards Preview

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Flashcards in Topic 4- Forces And Energy Deck (20):
1

What is the equation for work done?

Work done= force x distance
Joules= Newton’s x meters

2

What is the equation for power?

Power= work done/time taken
Watts= joules/seconds

3

What is the equation for a moment?

Moment of a force = force x distance
Newton meters = Newton’s x metres

4

What does the principle of moments state?

The sum of the clockwise moments=the sum of the anti-clockwise moments

5

Name the 8 energy stores

Kinetic
Thermal
Chemical
Gravitational potential
Elastic potential
Electrostatic
Magnetic
Nuclear

6

What happens when a system changes?

Energy is transferred

7

What is the equation for efficiency?

Useful energy transferred

8

Define power and it’s unit

Rate of energy transfer
Watt

9

What happens when there is more power?

The more work it does each second

10

Define force

A push or pull on an object that is caused by it interacting with something

11

Name the two types of forces

Non contact
Contact

12

What is Newton’s 3rd law?

Both objects feel an equal but opposite force

13

What does a free body force diagram show?

An isolated body and all the forces acting on it

14

Define resultant force

The overall force on an object or point

15

What do scale drawings do?

Find resultant forces

16

What are the 3 steps to drawing a scale drawing?

1) draw all the forces acting on an object
2) draw a line from the start of the last force to the end of the last force
3)measure the length of the resultant force on the diagram to find the magnitude of the force and the angle to find the direction

17

Define moment

Turning effect of a force

18

Define a lever

Levers transfer the turning effect of a force - push one end of a lever down and the rotation around the pivot causes the other end to rise

19

Define gears

Circular cogs with “teeth” around their edge

20

What are gears used for?

To transmit the rotational effect of a force from one place to another