Flashcards in Section 1 - Motion, Forces and Conservation of Energy Deck (46):

1

## What are vectors?

### Quantities with both magnitude and direction.

2

## What are scalars?

### Quantities with magnitude only.

3

## What are some examples of vector quantities?

### Force, velocity, displacement, weight, acceleration and momentum.

4

## What are some examples of scalar quantities?

### Speed, distance, mass, energy, temperature and time.

5

## What is a distance, in physics, defined as?

### How far an object has moved.

6

## What is displacement, in physics, defined as?

### The distance and direction in a straight line from an object's starting point to it's finishing point.

7

## What is speed, in physics, defined as?

### Speed is a measure of how fast something is going.

8

## What is velocity, in physics, defined as?

### How fast something is going and in what direction.

9

## Describe the formula relating (average) speed & time.

###
d=s×t

d = distance

s = (average) speed

t = time

10

## What is acceleration, in physics, defined as?

### The change in velocity over a certain amount of time.

11

## What is uniform acceleration, in physics, defined as?

### Speeding up (or slowing down) at a constant rate.

12

## Describe the formula relating acceleration, time and change in velocity.

###
a=(v-u)/t

a = acceleration

v = final velocity

u = initial velocity

t = time

13

## Describe the formula for constant acceleration.

###
v²-u²=2×a×x

v = final velocity

u = initial velocity

a = acceleration

x = distance

14

## Which graph shows how far something has traveled?

### Distance/Time graphs.

15

## Which graph can have both positive and negative gradients?

### Velocity/Time graphs.

16

## In a distance/time graph, how can speed be worked out?

### Speed = gradient = change in y / change in x

17

## In a velocity/time graph, how is distance worked out?

### By calculating the area under the graph.

18

## What is Isaac Newton's first law?

### Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed on it.

19

## Describe the equation relating resultant force and acceleration.

###
F=m×a

F = resultant force

m = mass

a = acceleration

20

## List some safety features used in cars.

### Seat belts, air bags and crumple zones.

21

## What is mass, in physics, defined as?

### The amount of 'stuff' in an object.

22

## What is weight, in physics, defined as?

### Mass with gravity.

23

## Describe the equation for weight.

###
W=m×g

W = weight

m = mass

g = gravitational field strength

24

## What is Isaac Newton's second law?

### Force is equal to the change in momentum per change in time. For a constant mass, force equals mass times acceleration.

25

## What is inertia?

### Inertia is the tendency for motion to remain unchanged.

26

## What is Isaac Newton's third law?

### For every action, there is an equal and opposite reaction.

27

## What is momentum, in physics, defined as?

### The property that all moving objects have.

28

## Describe the equation for momentum.

###
p=m×v

p = momentum

m = mass

v = velocity

29

## How, in a closed system, is momentum affected after an event. What is it called.

### It isn't, momentum before an event is equal to the momentum after the event. This is known as conservation of momentum.

30

## Describe the equation relating force & change in momentum.

###
F=(mv-mu)/t

F = force

m = mass

v = final velocity

u = initial velocity

t = time

31

## List the types of Energy Store.

###
Kinetic

Thermal

Chemical

Gravitational Potential

Elastic Potential

Electrostatic

Magnetic

Nuclear

32

## Describe the equation for working out the work done by a vehicle's brakes.

###
1/2×m×v²=F×d

m = vehicle's mass

v = velocity

F = braking force

d = braking distance

33

## Describe the equation for kinetic energy.

###
KE=1/2×m×v²

KE = Kinetic Energy

m = mass

v = velocity

34

## What is Kinetic Energy?

### Energy which a body possesses by virtue of being in motion.

35

## Describe the equation for a change in Gravitational Potential Energy.

###
ΔGPE=m×g×Δh

ΔGPE = change in Gravitational Potential Energy

m = mass

g = gravitational field strength

Δh = change in height

36

## What is Gravitational Potential Energy?

### Gravitational Potential Energy is energy an object possesses because of its position in a gravitational field.

37

## What is Conservation of Energy?

### The fact that energy can neither be created or destroyed.

38

## List the four main methods of energy transfer.

###
Mechanically

Electrically

By heating

By Radiation

39

## How is energy made useful?

### By transferring it into a useful store.

40

## Describe the equation for efficiency.

###
efficiency=

useful energy transferred by device/

total energy supplied to device

41

## How can efficiency be increased?

### By removing unwanted energy transfers.

42

## How can unwanted energy transfers be removed?

### Lubrication reduces energy transfer by friction. Insulation reduces energy transfer by heating.

43

## List the types of energy sources. Are they renewable or non-renewable? polluting or non-polluting?

###
Fossil fuels, non-renewable, polluting

Nuclear, non-renewable, polluting

Bio-fuels, renewable, polluting

Wind, renewable, non-polluting

The sun, renewable, non-polluting

Hydro-electric, renewable, non-polluting

Tides, renewable, non-polluting

44

## What are current trends in Energy Resource use?

### Currently we depend on fossil fuels, followed closely by nuclear fuels. However, we are slowly drifting towards renewable, non-polluting fuels like wind and solar.

45

## How much energy is produced in the UK by renewable resources?

### 15%

46