1.1 Basic physics

Question 1

What are the six base quantities and their units?

Answer 1

• mass (kg)
• length (m)
• time (s)
• electric current (A)
• temperature (K)
• amount of substance (mol)

Question 2

What is the base SI unit of volume?

Answer 2

m^3

Question 3

What is the base SI unit of density?

Answer 3

kg m-3

Question 4

What is the base SI unit of velocity?

Answer 4

ms-1

Question 5

What is the base SI unit of acceleration?

Answer 5

ms-2

Question 6

What is the base SI unit of force?

Answer 6

kg ms-2

Question 7

What is a scalar quantity?

Answer 7

quantity that has magnitude only.

Question 8

What is a vector quantity?

Answer 8

a quantity which has both magnitude and direction.

Question 9

What are coplanar vectors?

Answer 9

Vectors acting on the same plane as each other

Question 10

How do we find the resultant force of two forces acting at right angles to each other?

Answer 10

Pythagoras theorem

Question 11

How do we find the vertical component?

Answer 11

Sinθ

Question 12

How do we find the horizontal component?

Answer 12

Cosθ

Question 13

How do we find the homogeneity of an equation?

Answer 13

compare SI units

Question 14

What is the equation for density?

Answer 14

p = M/V

Question 15

What is the volume of a sphere?

Answer 15

4/3 π r³

Question 16

What is the moment of a force about a point?

Answer 16

the force × the perpendicular distance from the point to the line of action of the force.

Question 17

What conditions must be true for a body top be in equilibrium?

Answer 17

the sum of anticlockwise moment must be equal to the sum of anticlockwise moments

Question 18

What is the centre of gravity?

Answer 18

the point where all mass of an object is considered to act

Question 19

What are the conditions that must be true for a body to be in equilibrium?

Answer 19

• no net forces
• no net moment