P2.3 & P2.4 Motions And Forces And Momentum, Energy, Work And Power

Question 1

A runner runs a 400m race on a track. What is his distance and displacement?

Answer 1

Distance: 400m
Displacement: 0m

Question 2

On a distance-time graph, what does the gradient of the line show?

Answer 2

Speed

Question 3

How do you calculate speed?

Answer 3

Distance(m) / time taken(s)

Question 4

How do you calculate acceleration?

Answer 4

Change in velocity / time taken

Question 5

What are the units for acceleration?

Answer 5

m/s2

Question 6

Which of these values is not acceleration?

-2.3m/s2
100000000m/s2
1.5m/s2

Answer 6

All of them are acceleration

Question 7

On a velocity-time graph, what does a straight line show?

Answer 7

Constant velocity

Question 8

What is a vector quantity?

Answer 8

A quantity which has size and direction

Question 9

What forces can act on an object moving in the air?

Answer 9

Drag
Thrust
Upthrust
Weight

Question 10

When are forces balanced?

Answer 10

When the two forces acting against each other are the same

Question 11

What factors affect acceleration?

Answer 11

Mass
Force
Friction

Question 12

What is the formula for force?

Answer 12

Mass*acceleration

Question 13

What are the units for force?

Answer 13

Newtons, N

Question 14

What is terminal velocity?

Answer 14

The velocity an object reaches when it falls when it cannot accelerate any further

Question 15

What are the units for gravitational field strength?

Answer 15

Newtons per kilogram, N/Kg

Question 16

What is the formula for weight?

Answer 16

Mass*gravitational field strength

W=m*g

Question 17

What is thinking distance?

Answer 17

The distance that a car moves in the time that it takes a driver to react

Question 18

What is braking distance?

Answer 18

The distance a car travels between the driver braking and it stopping

Question 19

What is stopping distance?

Answer 19

Thinking distance*Braking distance

Question 20

What factors affect thinking distance?

Answer 20

State of the driver eg
Alcohol
Caffeine
Drugs
Illness

Question 21

What factors affect braking distance?

Answer 21

Road condition
Tyre condition
Velocity
Mass

Question 22

What is the formula for momentum?

Answer 22

Mass*velocity

Kg m/s = Kg*m/s

Question 23

What are crumple zones on a car?

Answer 23

Crumple zones are parts of the front on a car that can crumple on impact, which absorbs some of the energy in a crash

Question 24

What is the formula for force relating to momentum?

Answer 24

Force = Change in momentum / time taken
F= mv-mu / t
N= kgm/s / s

Question 25

What is the formula for work done?

Answer 25

Work done = force * distance moved E= F*d J= N*m

Question 26

What is the formula for power?

Answer 26

``` Power = work done / time taken P = E / t W= J / s ```

Question 27

What is the formula for Gravitational potential energy?

Answer 27

``` GPE = mass * GFS * vertical height GPE= m * g * h J = kg* N/kg * m ```

Question 28

What is the formula for kinetic energy?

Answer 28

``` KE = 1/2 * mass * velocity2 KE = 1/2 * m * v2 J= 1/2 * kg * m/s2 ```

Question 29

What Is conservation of energy?

Answer 29

The GPE is the same as KE when it is transferred

Question 30

How can you calculate distance from a velocity-time graph?

Answer 30

Velocity * time on the area underneath the line on the graph

Question 31

Why can a space probe travel without fuel?

Answer 31

There is no air in space to slow it down

Question 32

What is negative acceleration?

Answer 32

Slowing down

Question 33

What is the effect of a tired driver on stopping distance?

Answer 33

It increases