Page 144 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Significant learning outcomes

The learner can
explain what force is and what the results of applying a force
are.

identify different types of forces and classify them into
contact and noncontact forces.

explain friction and identify its advantages and
disadvantages and use it in daily life situations.
explain thrust and pressure.

use the relation between area and pressure in appropriate
situations.

explain liquid pressure and engage in experiments that show
the relation between pressure and height.
explain what atmospheric pressure is and use it
appropriately in daily life situations.

Let us assess

1. Classify the following situations into contact and noncontact
forces.

a. Applying break in a bicycle.
b. A mango falling from a mango tree.
c. The earth revolving around the sun.

d. The speed of a ball rolling on ground is reduced.
2. State reason

a. We are able to walk on the ground without slipping.
b. It is easy to cut vegetables using a sharp knife.
c. The number of tyres is more for goods vehicles.

d. The moving parts of machines experience wear and tear.
3. Match the following
A B C

Atmospheric pressure pascal coconut oil
Lubricant attraction barometer
Coconut falling down bar thermometer
Magnet friction noncontact
gravitation repulsion

Basic Science VIII 143