Question

SECTION B (UNDERSTANDING)
5. When the distance-time graph of a body is depicted as a straight line parallel to time
axis. The body will be
(a) moving with constant speed
(b)moving with constant velocity
(c)at rest
(d). Moving in straight line. Give logic for your answer.


6.Differentiate between speed and velocity of a body. Out of the two which have the zero mean
value for a moving body? Give one example.​

Answer 1

Slope of a displacement-time graph with time axis measures velocity.

The graph being a straight line implies uniform slope throughout.

So, the body moves with uniform velocity.

Hope this helps you

Explanation:

1. speed is a scalar quantity and velocity is a vector

2. speed is distance/time and velocity is displacement /time

3. speed can be equal to or greater than velocity whereas velocity can be zero or lesser than or equal to speed

Out of the two only the mean value of velocity can be zero

Eg:when initial and the final positions are same