Page 130 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Significant learning outcomes

The learner can
distinguish between state of rest and state of motion with
reference to the reference body.
differentiate between distance and displacement and
describe the situation in which their measures are equal.

recognise that physical quantities having direction along
with magnitude are vector quantities and others are scalar
quantities and give examples for the same.

distinguish speed from velocity and describe both.

describe and find out examples for uniform speed, non-
uniform speed, uniform velocity, non-uniform velocity,
acceleration and retardation and solve mathematical
problems based on them.

explain the measures to be taken for road safety and engage
in activities related to them.

Let us assess

1. Which of the following does not belong to the group?
(velocity, acceleration, speed, displacement)

2. The statement of a child is as follows: “My displacement is
zero though I ran 250 m”. What is meant by this?
3. All objects having uniform speed need not have uniform
velocity. Describe with the help of examples.

4. Bus A covered 75 m in 5 s. Bus B covered 169 m in 13 s
a. Which bus covered a greater distance?

b. Which bus has a higher speed?
5. What is the acceleration of a car which started from rest and
acquired a velocity of 40 m/s in 8 s?
6. A car covered the first 400 m distance with a speed of
8 m/s, the next 1200 m with a speed 12 m/s and the last
360 m with a speed of 12 m/s. Calculate the average speed
of the car.

7. Does a body have acceleration in the following situations?
Why?

Basic Science VIII 129