Mechanics

Question 1

Speed

Answer 1

Is the rate of change of distance with respect to time

Question 2

Displacement

Answer 2

Is distance in a given direction

Question 3

Velocity

Answer 3

Is the rate of change of displacement with respect to time

Question 4

Constant Velocity

Answer 4

Is if an object moves in a straight line and does not speed up or slow down

Question 5

Acceleration

Answer 5

Is the rate of change of velocity with respect to time ( can be +ve or -ve)

Question 6

Scalary quantity

Answer 6

Is a quantity that has magnitude only and has no direction in space e.g speed

Question 7

Vector Quantity

Answer 7

Is a quantity that has both magnitude and a direction in space e.g velocity

Question 8

Force

Answer 8

Is any interaction that causes the velocity of an object to change

Question 9

Mass

Answer 9

Is a measure of how difficult it is to accelerate an object

Question 10

Weight

Answer 10

Is the force of the Earth’s gravity acting on an object

W=mg

Question 11

Newton’s 1st law

Answer 11

Every object will remain in a state of rest or moving at a constant velocity unless an unbalanced external force acts on it

Question 12

Newton’s 2nd law

Answer 12

When an unbalanced external force acts on an object the rate of change of the objects momentum is directly proportional to the force and takes place in the direction of the force

F =m(v-u/t)

Question 13

Newton’s 3rd law

Answer 13

If an object A exerts a force on an object B,the object B exerts an equal but opposite force on object A

I.e Action and Reaction are Equal and Opposite.Leads to conservation of momentum in closed systems.

Question 14

Conservation of momentum

Answer 14

Is any interaction between two (or more) objects ,the total momentum before the interaction is equal to the total momentum after,provided no external forces act on the system of objects.

m1u1 + m2u2 = m1v1 + m2v2

Question 15

Density

Answer 15

Is the mass per unit volume of a substance

D= M/V

Question 16

Pressure

Answer 16

Is the force per unit area

P = F/A

Question 17

Archimedes principle

Answer 17

When an object is partially or completely immersed in a fluid it experiences an upthrust equal in magnitude to the weight of the fluid it displaces

Question 18

Law of flotation

Answer 18

The weight of a floating object is equal to the weight of the fluid it displaces

Question 19

Boyle’s law

Answer 19

At constant temperature the volume of a fixed mass of gas is inversely proportional to it’s pressure

Question 20

Newton’s gravitational law

Answer 20

Any two point masses in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them

F = G m1m2/ d²

Question 21

Moment of a force

Answer 21

Is the magnitude of the force (Abt an axis) multiplied by the perpendicular distance from the fulcrum/rotation axis,to the line of action of the force

M = F * d

Question 22

A couple

Answer 22

Is two parallel forces with the same magnitude acting in opposite directions

Question 23

Work

Answer 23

Is done when a force moves an object through a displacement in the direction of the force and is equal to the force multiplied by the displacement

W = F * d

Question 24

Energy

Answer 24

Is the ability to do work

Question 25

Conservation of energy

Answer 25

In a closed system energy cannot be created or destroyed but only converted from one form to another

Question 26

Kinetic energy

Answer 26

Is the energy that an object has due to its motion E = 1/2 mv²

Question 27

Potential Energy

Answer 27

Is the energy that an object has due to its shape or position in a force field

Question 28

Power

Answer 28

Is the rate at which work is done or the rate at which energy is given out or taken in P = W/t

Question 29

Renewable Energy

Answer 29

Is a source of energy that will not be depleted over humanity's lifetime