Samacheer Kalvi solutions for Science [English] Class 8 TN Board chapter 2 - Force and Pressure [Latest edition]

If we apply force against the direction of motion of the body, then the body will

Pressure exerted by a liquid is increased by

Unit of pressure is 

The value of the atmospheric pressure at sea level is

Pascal’s law is used in

Which of the following liquids has more viscosity?

The unit of viscosity is

The pressure of a liquid column ______ with the depth of the column.

Hydraulic lift works under the principle of _______.

The property of _______ of a liquid surface enables the water droplets to move upward in plants.

A simple barometer was first constructed by _______.

Force acting on a given area is called pressure.

A moving body comes to rest due to friction alone.

A body will sink if the weight of the body is greater than the buoyant force.

One atmosphere is equivalent to 1,00,000 newton force acting on one square metre.

Rolling friction is slightly greater than sliding friction.

Friction is the only reason for the loss of energy.

Liquid pressure decreases with the decrease of depth.

Viscosity depends on the pressure of a liquid.

Match the following.

Match the following.

Complete the analogy.

Knot in a thread : _____ friction : : Ball bearing : _____ friction

Complete the analogy.

Downward force: Weight:: Upward force offered by liquid: _____

Numerical Problem.

A stone weighs 500 N. Calculate the pressure exerted by it if it makes contact with a surface of area 25 cm².

Consider the statement given below and choose the correct option.

Assertion: Sharp knives are used to cut the vegetables.

Reason: Sharp edges exert more pressure.

Consider the statement given below and choose the correct option.

Assertion: Broad straps are used in bags.

Reason: Broad straps last for long.

Consider the statement given below and choose the correct option.

Assertion: Water strider slides easily on the surface of the water.

Reason: Water strider experiences less buoyant force.

Give two examples to verify that a force changes the shape of a body.

Give two examples to verify that a force tends to change the static condition of a body.

How do you feel when you touch a nail immediately after it is hammered into a wooden plank? Why?

How does the friction arise between the surfaces of two bodies in relative motion?

Name two instruments, which help to measure the pressure of a fluid.

Define one atmosphere.

Why are heavy bags provided with broad straps?

How does surface tension help a plant?

Which has greater viscosity, oil or honey? Why?

Define friction. Give two examples of the utility of friction in day-to-day life.

Mention any three ways of minimizing friction.

State Pascal's law.

Mention the application of Pascal's law.

Why is a ball bearing used in a cycle hub?

Friction is a necessary evil - Explain.

Give the different types of friction and explain each with an example.

Describe an experiment to prove that friction depends on the nature of a surface.

Explain how friction can be minimized.

Describe an experiment to prove that the pressure in a liquid increase with depth.

Why is it not advisable to use a fountain pen while travelling in an aeroplane?

Is there any possibility of making a special device to measure the magnitude of friction directly?

Vidhya feels that mercury is costly. So, instead of mercury she wants to use water as a barometric liquid. Explain the difficulty of constructing a water barometer.