Question

Example 8.3 Usha swims in a 90 m long
pool. She covers 180 m in one minute
by swimming from one end to the other
and back along the same straight path.
Find the average speed and average
velocity of Usha.
​

Answer 1

Answer:

Average speed = 3 ms⁻¹

Average velocity = 0 ms⁻¹

Explanation:

Total distance covered by usha in 1 minute = 180 metres

Displacement of Usha in 1 minute = 0 metres

Average speed = Total distance covered / total time taken

= 180/1 min

1 min = 60 seconds

180/60 = 3 m s⁻¹

Average velocity = Displacement / time taken

0/60 seconds

= 0ms⁻¹

The average speed of Usha is 3 ms⁻¹ and average velocity is 0 ms⁻¹

Answer 2

Length of the pool: 90m

Average speed:

Speed= Distance/Time

speed=180/60

speed=30 m/s

Velocity:

velocity=displacement/time

displacement=0( Since she comes back to the same place)

velocity=0

Hope it helps....