P 11 - Pressure And Force

Question 1

Units for pressure

Answer 1

Pascals, N/m^2

Question 2

To work out pressure

Answer 2

Force( N newtons) divided by Area (m^2

Question 3

Pressure in liquids depends on:

Answer 3

• Depth of the liquid means pressure increases.

- Density of the liquid increases pressure.

Question 4

If a force of 10N is applied through a piston of 1cm2 to liquid, the pressure applied to the liquid will be:

Answer 4

10N / cm^2 because liquids cannot be squashed

Question 5

What does pressure in gases create

Answer 5

Atmospheric pressure.

Question 6

Principle of pressure

Answer 6

A forces affect on an object will often depend on the concentration or distribution of the force. It it is distributed over a large area, the pressure will be less than on a small area.

Question 7

An object floats if:

Answer 7

An object floats if its weight is equal to the upthrust, as the forces are balanced. If its weight is more than the upthrust, the object sinks.
Whether or not the object floats depends on its density. If the object is less dense than the fluid then it displaces a volume of the fluid and floats. If it is more dense, it cannot displace the volume of water, so it sinks.

Question 8

Units of density

Answer 8

Kg/m^3

Question 9

Why does atmospheric pressure decrease with height?

Answer 9

There are more particles to collide with an object lower down, creating more atmospheric pressure

Question 10

Pressure in liquids

Answer 10

Gravitational field strength X density X depth