Question 1

A system has a pressure of 5 N/m^2

If a force of 2000 N is applied, what is the area that the force is applied to?

ANSWER: Simple text answer

Answer: 400 m^2

Workings:

\dfrac{2000 \space N}{5 \space Nm^{-2}}  = 400 m^2

Marks = 2


Question 2

The force applied to a 0.4 m by 0.8 m break pad produces a pressure of 500 N/m^2.

Calculate the force applied to the break pad.

ANSWER: Simple text answer

Answer: 160 N

Workings:

Area = 0.4 \times 0.8 = 0.32 m^2

500 \times 0.32 = 160 N

Marks = 2


Question 3

An object exerts a force of 10 kN on an area of 2 cm^2.

What is the pressure the object exerts on the surface?

Give the units of pressure.

ANSWER: Simple text answer

Answer: 5000 Ncm^{-2}

Workings:

\dfrac{10000}{2} = 5000 Ncm^{-2}

Marks = 1


Question 4

Our atmosphere exerts a pressure of 101 N/m^2.

Calculate the force on one square centimetre caused by the atmosphere.

Give your answer in Newtons to 3 significant figures.

ANSWER: Simple text answer

Answer: 0.0101 Ncm^{-2}

Workings:

101 Nm^{-2} = 0.0101 Ncm^{-2}

Marks = 1


Question 5

A crate in a Wearhouse exerts a 10,000 N force on the floor.

Calculate the pressure on the warehouse floor caused by the crate.

Give your answer in Newtons to 3 significant figures.

ANSWER: Simple text answer

Answer:

Workings:

Area = 0.5 \times 3 = 1.5 m^2

\dfrac{10000}{1.5} = 6670 Nm^{-2}

Marks = 2


Question 6

A needle requires a force of 0.5 Newtons to puncture the skin.

The tip of the needle has an area of  0.0000001 m^2

Calculate the pressure needed to puncture the skin?

ANSWER: Simple text answer

Answer: 5 \times 10^6  Nm^{-2}

Workings:

\dfrac{0.5}{0.0000001} = 5 \times 10^6  Nm^{-2}

Marks = 2


Question 7

A coin is dropped off of a building landing on its side.

It hits with a pressure of 400N/m^2

It hits with a force of 0.1 N

Calculate the area of the coin?

ANSWER: Simple text answer

Answer: 2.5 \times 10^{-4} m^2

Workings:

\dfrac{0.1}{400} = 2.5 \times 10^{-4} m^2

Marks = 2


Question 8

A cylinder sands on the circular end.

The cylinder exerts a force of 2 N onto the floor.

The cylinder has a radius of 0.5 m

Calculate the pressure the cylinder exerts on the floor.

Give your answer to 3 significant figures.

ANSWER: Simple text answer

Answer: 2.55 Nm^{-2}

Workings:

Area = \pi \times 0.5^2 = 0.25 \pi m^2

\dfrac{2}{0.25\pi} = 2.55 Nm^{-2}

Marks = 2