Definitions and Laws

Question 1

What is Efficiency?

Answer 1

[…] is a measure of how good a device is at changing energy from one (type) to another (type).

Question 2

What is the Law of Conservation of energy?

Answer 2

Energy can not be created or destroyed, only transferred from one type to another.

Question 3

What is Work?

Answer 3

[…] is the amount of energy transformed when a force is moved/when a force moves.

Question 4

What is a vector and scalar quantity and the difference between them?

Answer 4

A […] quantity has both magnitude and direction, whereas a […] quantity only has a magnitude.

Question 5

What is Newton’s 3rd Law.

Answer 5

Every action has an opposite but equal reaction.
action - reaction pairs (have to be the same type of force).

Question 6

What is the centre of mass?

Answer 6

The point at which all the mass of an object seems to be concentrated.

Question 7

What is Equilibrium?

Answer 7

An object as rest is in Equilibrium. The key conditions for an object to be considered in Equilibrium are:
The resulatant forces on the object is zero.
The forces acting on the object have no overall turning effect.

Question 8

What is acceleration?

Answer 8

[…] is the change of measurement in an object.

Question 9

What is stopping distance?

Answer 9

[…] is how long a vehicle will travel between the moment the driver sees a danger and brakes hard and when the car will come to a complete stop.

Question 10

Hooke’s Law

Answer 10

[…] states that the force is proportional to the extencion.
If you change the force acting, the extension will change by the same factor.

Question 11

What is specific heat capacity

Answer 11

[…] is the thermal energy required to raise the temperature of a body of mass 1Kg by 1K (or 1°C).