Compound measures for pressure | Maths | Quizalize & Oak National Academy

Starter quiz

The density of a substance is measured as the substance's ______ per unit of volume.

'mass' ✓
The volume of an object is 125 cm $^3$ and has a mass of 687.5 g. The density of the object is ______ g/cm $^3$

'5.5' ✓
Match each with its correct density.

Mass = 0.96 kg and volume = 0.8 m $^3$

⇔

1.2 kg/m $^3$ ✓

Mass = 8880 g and volume = 74 cm $^3$

⇔

120 g/cm $^3$ ✓

Mass = 288 g and volume = 24 cm $^3$

⇔

12 g/cm $^3$ ✓

Mass = 0.144 g and volume = 1.2 cm $^3$

⇔

0.12 g/cm $^3$ ✓
The density of an object is 15 g/cm $^3$ , the mass of the object is 487.5 g. The volume of the object is ______ cm $^3$

'32.5' ✓
The density of an object is 5.6 g/cm $^3$ , the volume of the object is 160 cm $^3$ . Calculate the mass of the object. (Give your answer in grams)

'896 g' ✓
The density of this cuboid is 1.8 g/cm $^3$ . Calculate the mass of the cuboid.

'324 g' ✓

Exit quiz

Which of the following are units of pressure?

g/cm $^3$

N/m $^2$ ✓

m/s

kg/m $^3$

N/cm $^2$ ✓
A box is placed on a table. The area of the base of the box is 1.25 m $^2$ . The force exerted by the box on the table is 38 N. The pressure exerted by the box on the table is ______ N/m $^2$ .

'30.4' ✓
Match each with its correct pressure.

Force = 260 N and area = 2.5 m $^2$

⇔

104 N/m $^2$ ✓

Force = 450 N and area = 4 m $^2$

⇔

112.5 N/m $^2$ ✓

Force = 104 N and area = 1.6 m $^2$

⇔

65 N/m $^2$ ✓

Force = 564 N and area = 6 m $^2$

⇔

94 N/m $^2$ ✓
This box has a mass of 112 N. Calculate the pressure it exerts on the ground.

0.93 N/cm $^2$

2.8 N/cm $^2$ ✓

4.6 N/cm $^2$

8.6 N/cm $^2$
The pressure exerted by a cube with side lengths of 5 cm on a table is 2.85 N/cm $^2$ . Find the force exerted by the cube on the table.

'71.25 N' ✓
This box exerts a pressure of 80 N/m $^2$ and a force of 76.8 N on the ground. How wide is the box?

'0.8 m' ✓

Worksheet

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Lesson Details

Key learning points

Pressure can be calculated by dividing the force on the objects by the area on which the force acts.
The units for force and area determine the units for pressure.
By rearranging the formula, you can calculate either force or area.

Common misconception

Using the total surface area of the solid rather than the area of the solid that is in contact with the floor/table.

Refer back to the high-heeled shoe and elephants foot example. This should clarify that it is the area in contact with the foot that increases or decreases the pressure.

Keywords

Pressure - Pressure is the perpendicular force applied to the surface of an object per unit area over which that force is distributed.
Force - A force is a push or a pull on an object. A force is an influence that can cause an object to change its speed.