Traffic test 2020

Question 1

What types of forces are gravity, electrical and magnetic?

Answer 1

Gravity is attractive

Electrical is attractive and repulsive

Magnetic forces are attractive and repulsive

Question 2

What is the difference between weight and mass?

Answer 2

The mass of an object is a measure of the object’s inertial property, or the amount of matter it contains. The weight of an object is a measure of the force exerted on the object by gravity, or the force needed to support it.
1 newton can support 100 grams so 10 newtons can support 1 kilogram. To find the force acting upon someone, multiply their mass in kg by 10.

Question 3

What is newtons 1st law?

Answer 3

Newtons first law states that every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

Question 4

What is Newtons 2nd law?

Answer 4

The second law states that the relationship between an objects mass m, its acceleration a, and the applied force f, is F = M x A.

Question 5

What is newtons third law?

Answer 5

The third law states if object A exerts a force on object B, then object B exerts an equal-sized force on object A in the opposite direction.

Question 6

What are the two important aspects about forces?

Answer 6

The size of the force and direction of the force.

Question 7

How is the net force of an object described?

Answer 7

The net force of an object is the sum of all forces acting on an object. If the net force is 0 the object is balance but if any higher the object is unbalanced. For example if an object is pulled 2400N to the left, 2400N to the right and 2600N up the net force would be 200N up whilst being unbalanced.

Question 8

1. What is the net force on a ball thrown on the way up?
2. What is the net force on a ball thrown at the max height?

What is the net force on a ball thrown on the way down

Answer 8

1. Net force = down
2. Net force = down
3. Net force = down

Question 9

What happens in a car crash?

Answer 9

In a car crash equal force is exerted on both vehicles as stated by law 3 and passengers will fly forward as they were moving at a pace whilst coming to a stop so abruptly.

Question 10

What is friction?

Answer 10

Friction occurs when an object moves over another or through a liquid or gas. It produces heat (rubbing hands), opposes and slows down motion (brake pads) and causes objects to wear (engines).

Question 11

What is air resistance?

Answer 11

Air resistance is friction but in air, it opposes all objects that move through air, but only seriously slows an object at higher speeds.

Question 12

What is the formula to calculate average speed?

Answer 12

Speed = Distance / Time

D = S x T

T = D / S

Question 13

Give an example of average speed.

Answer 13

A runner runs 440 metres in 52 seconds. His average speed in 440 / 52 = 8.46 metres per second.

Question 14

What is the conversion from m/s to km/h?

Answer 14

To convert from m/s to km/hr multiply by 3.6.
e.g. 12 m/s is 12 x 3.6 = 39.6 km/hr.

To convert from km/h to m/s divide by 3.6.
e.g. 100 km/hr is 100 / 3.6 = 27.8 m/s

Question 15

Apply the average speed formula.

Answer 15

Time taken = 1.5 hours
Average speed = 90 km/hr
Distance = 1.5 x 90 = 135km

Question 16

What factors may affect the stopping distance of a car?

Answer 16

Thinking distance, reaction speed, quality of break pads, what type of road, influence of alcohol, tired or not and any distractions such as mobile phones,

Question 17

Can average speed be found a different way?

Answer 17

Yes it can be found by dividing change in velocity by 2.

U = initial velocity, V = final velocity.

U + V
2

Question 18

How is acceleration found?

Answer 18

Acceleration = change in velocity / time taken.

Change in velocity
Acc Time

Question 19

Give an example of calculating acceleration.

Answer 19

A truck increases it speed from 11 cm/s to 89 cm/s in 5 seconds.

A = 89 - 11
5 = 15.6

Question 20

Give an example of calculating deceleration.

Answer 20

A car goes from 133 cm/s to 26 cm/s in 0.8 seconds.

A = 26 - 133
3 = -35.67

Question 21

What is the formula to find force, mass and acceleration?

Answer 21

F = M x A

F / M = A

F / A = M

Question 22

What is the time interval between each dot on a ticker timer tape?

Answer 22

0.02 seconds

Question 23

How much time does 6 dots on a ticker timer represent?

Answer 23

5 gaps so 0.1 second

Question 24

How does one find weight when given mass in kg

Answer 24

W = m x g (10N x every kg)