Force and Pressure — Practice

Question 1

The unit of pressure is (a) pascal (b) N m⁻² (c) both pascal and N m⁻².

Accepted Answer

(c) both pascal and N m⁻².

Question 2

The atmospheric pressure at sea level is (a) 76 cm of mercury (b) 36 cm (c) 100 cm.

Accepted Answer

(a) 76 cm of mercury column.

Question 3

The property of ________ of a liquid surface helps water move upward in plants.

Accepted Answer

surface tension.

Question 4

True or False: Rolling friction is slightly greater than sliding friction.

Accepted Answer

False — rolling friction is slightly less than sliding friction.

Question 5

A force of 100 N acts on an area of 2 m². Find the pressure.

Accepted Answer

P = F/A = 100/2 = 50 Pa.

Question 6

What is viscosity? Give an example of a highly viscous liquid.

Accepted Answer

Viscosity is the resistance of a liquid to flow; grease (or honey) is highly viscous.

Question 7

State Pascal's law and give one application.

Accepted Answer

Pressure applied to an enclosed fluid is transmitted equally in all directions; it is used in the hydraulic lift (also brakes).

Practice — Force and Pressure