P10

Question 1

What is inertia

Answer 1

The tendency of objects to continue in their state of rest or of uniform motion is called inertia

Question 2

What is newton’s first law

Answer 2

If the resultant force acting on an object is zero and:
The object is stationary, the object remains stationary
The object is moving, the object continues to move at the same speed and in the same direction. So the object continues to move at the same velocity

Question 3

What is newtons second law

Answer 3

The acceleration of an object is proportional to the resultant force acting on the object, and inversely proportional to the mass of the object.

Question 4

Newtons 3rd law

Answer 4

Whenever two objects interact, the forces they exert on each other are equal and opposite

Question 5

What js the stopping distance

Answer 5

The stopping distance of a vehicle is the sum of the distance the vehicle travels during the driver’s reaction time (thinking distance) and the distance it travels under the braking force (braking distance).
For a given braking force the greater the speed of the vehicle, the greater the stopping distance

Question 6

What is the reaction time for typical person

Answer 6

values range from 0.2 s to 0.9 s

Question 7

How can a drivers reaction time be affected

Answer 7

A driver’s reaction time can be affected by tiredness, drugs and alcohol. Distractions may also affect a driver’s ability to react

Question 8

How can the braking distance of a vehicle be affected

Answer 8

The braking distance of a vehicle can be affected by adverse road and weather conditions and poor condition of the vehicle
Adverse road conditions include wet or icy conditions.
Poor condition of the vehicle is limited to the vehicle’s brakes or tyres

Question 9

What happens to the energy of a vehicle when a force is applied to the brakes

Answer 9

When a force is applied to the brakes of a vehicle, work done by the friction force between the brakes and the wheel reduces the kinetic energy of the vehicle and the temperature of the brakes increases

Question 10

Hiw does speed affect braking force

Answer 10

The greater the speed of a vehicle the greater the braking force needed to stop the vehicle in a certain distance

Question 11

How is deceleration inceased and what can it lead to

Answer 11

The greater the braking force the greater the deceleration of the vehicle. Large decelerations may lead to brakes overheating and/or loss of control

Question 12

What is the equation for momentum

Answer 12

momentum = mass × velocit y
p = mv

Question 13

How does momentum change after an event

Answer 13

In a closed system, the total momentum before an event is equal to the total momentum after the event
This is called conservation of momentum

Question 14

What is the equation for a force that is acting on a moving object

Answer 14

F = change in momentum/ time
F = mv - mu/ t
Force equals the rate of change in momentum

Question 15

How do safety features in cars work

Answer 15

E.g air bags, seat belts, crash helmets

Prolong impact time so decreases the rate of change in momentum

Question 16

How is the extension of a spring linked to the force applied

Answer 16

The extension of an elastic object, such as a spring, is directly proportional to the force applied, provided that the limit of proportionality is not exceeded

Question 17

Equation for force on an elastic object

Answer 17

force = spring constant × extension

F = k x e

Question 18

How is energy transferred throughout a spring

Answer 18

A force that stretches (or compresses) a spring does work and elastic potential energy is stored in the spring. Provided the spring is not inelastically deformed, the work done on the spring and the elastic potential energy stored are equa

Question 19

Equation for elastic potential energy

Answer 19

elastic potential energy = 0.5 × spring constant × extension^2
E = 1/2 x k x e^2