Basics of Physics

Question 1

What is a scalar

Answer 1

Quantity with only magnitude
Examples
Distance
Speed
Mass
Energy
Volume
Area
Pressure
Density

Question 2

What is a vector

Answer 2

Quantity with magnitude and direction
Examples
Displacement
Velocity
Force
Acceleration
Momentum
Electric current

Question 3

What is the horizontal component

Answer 3

x=Zcos(theta)

Question 4

What is the vertical component

Answer 4

x=Zsin(theta)

Question 5

Definition of centre of mass

Answer 5

Is the point representing the mean location of all the mass in a system

Question 6

Definition of centre of gravity

Answer 6

The centre of gravity is the single point within a body at which the entire weight of the body may be considered to act.

Question 7

What is a moment (torque)

Answer 7

The turning effect about a pivot

Question 8

Equation for moments

Answer 8

Moment(Nm)=Force(N)x perpendicular distance from pivot(m)

Question 9

What is the principle of moments

Answer 9

When in rotational equilibrium,the sum of clockwise moments must equal the sum of anti-clockwise moments

Question 10

What does a closed vector triangle mean

Answer 10

Forces are in equilibrium

Question 11

What are the SI Base Units

Answer 11

Length - meter (m)
Time - second (s)
Amount of substance - mole (mole)
Electric current - ampere (A)
Temperature - kelvin (K)
Luminous intensity - candela (cd)
Mass - kilogram (kg)