Density and pressure

Question 1

Define density.

1 mark

Answer 1

Density is the Mass per unit Volume.

Question 2

What is the formula for density?

1 mark

Answer 2

Denity = Mass ÷ Volume

Question 3

What is density measured in?

2 marks

Answer 3

Either g/cm³ or kg/m³

Question 4

Liquid water has a density of 1.0g/cm³, while ice has a density of 0.92g/cm³.
Calculate the volume occupied by 250g of:
i) liquid water
ii) ice

6 marks

Answer 4

i) Volume = Mass ÷ Density
Volume = 250 ÷ 1
Volume = 250cm³

ii) V = M ÷ D
V = 250 ÷ 0.92
V = 271.74cm³

Question 5

Define pressure.

1 mark

Answer 5

Pressure is the Force per unit Area.

Question 6

What is the formula for pressure?

1 mark

Answer 6

Pressure = Force ÷ Area

Question 7

What is pressure measured in?

2 marks

Answer 7

Either N/m² or N/cm²

Question 8

What is an alternative for N/m²?

1 mark

Answer 8

1N/m² = 1 Pa (pascal)

Question 9

Find the pressure when the force applied is 200N and the surface area is 23cm².

3 marks

Answer 9

p = F ÷ A
p = 200 ÷ 23
p = 8.70N/cm²

Question 10

Calculate the area if an object creates a pressure of 25 Pa when acting from the force of 300N.

3 marks

Answer 10

A = F ÷ p
A = 3000 ÷ 25
A = 120m²

Question 11

Pressure acts at an angle of ……….°?

1 mark

Answer 11

90°

Question 12

The smaller the area the 1)………. the pressure. The larger the area the 2)………. the pressure.

2 marks

Answer 12

1. Higher
2. Smaller