Module 3 - Forces and Motion (Linear Motion)

Question 1

When are the equation of motion applicable

Answer 1

• Linear Acceleration

Question 2

what does the mneumonic suvat stand for

Answer 2

s - displacement
u - initial velocity
v - final velocity
a - acceleration
t - time

Question 3

What is the suvat equation with the abscence of displacement

Answer 3

v = u + at

Question 4

What is the suvat equation with the abscence of acceleration

Answer 4

s = 1/2(u+v)t

Question 5

What is the suvat equation with the abscence of final velocity

Answer 5

s = ut + 1/2 at^2

Question 6

What is the suvat equation with the abscence of time

Answer 6

v^s = u^2 + 2as

Question 7

Why does the mass of an object not affect the acceleration of it

Answer 7

A greater mass causes the gravitational force acting on a body to increase, meaning a stronger pull toward the Earth. However, a higher mass also has a proportionally greater resistance to acceleration (inertia). Since the pull and the resistance increase in the same proportion, the acceleration remains the same for all objects.

Question 8

What is meant by the term Stopping Distance

Answer 8

The distance travelled by a vehicle from the moment a person reacts to when the vehicle stops

Question 9

What is meant by the term Thinking Distance

Answer 9

The distance travelled by the car from when the person reacts to stop to when they press the brakes

Question 10

What is meant by the term braking distance

Answer 10

The distance travelled by the vehicle after the brakes are applied to when the vehicles stops

Question 11

How is the stopping distance calculated

Answer 11

Stopping distance = thinking distance + braking distance

Question 12

What is the typical range of reaction time

Answer 12

0.4s - 0.8s

Question 13

Derive proportionality between thinking distance and speed

Answer 13

1. because reaction speed has a a set range it can be called a constant.
2. this means that the equation d = s x t can be called as d = k s showing that thinking distance is directly proportional to the speed of the vehicle.

Question 14

Derive the proportionality between braking distance and speed

Answer 14

1. 0.5mv^2 = F x d because the work done by the brakes until the vehicle stops is equal to the intial kinetic energy store of the vehicle
   Constants: 0.5, m, F
2. k1 x v^2 = k2 d
3. v^2 = k d showing that the braking distance is directly proportinal to the square of the vehicle velocity

Question 15

What are factors affecting Stopping distance

Answer 15

1. condition of the brakes (F)
2. mass of the vehicle
3. the velocity of the vehicle
   4 Alcohol and Drugs