Topic 2 - Forces And Motion

Question 1

What is a vector?

Answer 1

A quantity with both magnitude (size) and direction

Question 2

What is a scalar?

Answer 2

A quantity with magnitude only

Question 3

Examples of vectors

Answer 3

Displacement, velocity, acceleration, force, weight, momentum

Question 4

Examples of scalers

Answer 4

Distance, mass, speed, energy

Question 5

What is the difference between speed and velocity?

Answer 5

Speed is scalar so it only has a magnitude but velocity is a vector so it has direction and magnitude

Question 6

What is the equation for speed?

Answer 6

Speed (m/s) = distance (m) / time (s)

Question 7

What is the equation for acceleration?

Answer 7

Acceleration (m/s2) = change in velocity (m/s) / time taken (s)
a = (v - u) 
            /t
V= final velocity 
U= initial velocity

Question 8

What is acceleration?

Answer 8

The change in velocity in a certain amount of time

Question 9

How do you find the speed on a curved distance time graph?

Answer 9

Draw a tangent to find the gradient. Use equation if finding distance.

Question 10

How do you find the distance travelled on a velocity time graph?

Answer 10

Find the area under the graph

Question 11

What is the value of acceleration due to gravity?

Answer 11

10 m/s2

Question 12

What is momentum?

Answer 12

The product of the objects mass and velocity

Question 13

What is the equation for momentum?

Answer 13

Momentum (kg m/s) = mass (kg) x velocity (m/s)

P= m x v

Question 14

What is Newton’s second law equation for force?

Answer 14

Force (N) = mass (kg) x acceleration (m/s2)

Question 15

What is the thinking distance?

Answer 15

The distance the car travels in the drivers reaction time

Question 16

What is thinking distance affected by?

Answer 16

Increased by tiredness, alcohol, drugs and distractions

Question 17

What is braking distance?

Answer 17

The distance taken to stop once the brakes have been applied

Question 18

What is braking distance affected by?

Answer 18

Speed of car, mass of car, friction between tyres and road, road conditions eg icy wet, or if tyres are worn

Question 19

Explain how human reaction time is measured using computer based test

Answer 19

Clicking and mouse when the screen changes colour and timing reaction time

Question 20

Explain how human reaction time can be measured using ruler drop test

Answer 20

One person holds top of ruler one person touches bottom. Top person drops it and the measurement is how far ruler dropped in time to react.

Question 21

What is the typical reaction time for ruler drop test

Answer 21

0.2s - 0.6s

Question 22

How do you find the stopping distance of a vehicle?

Answer 22

Thinking distance + braking distance