Question

A table clock has its minute hand 4 centimetre long .find the average speed and average velocity of the tip of the minute hand between 6 am to 6.30 am and 6 am to 6.30 pm?

Answer 1

Between 6 am to 6:30 am
Average speed = Total distance/ Time
= πr / (30 × 60 seconds)
= 4π/1800
= 0.00698 cm/s

Average velocity = Total displacement/ Time
= 2r / (30 × 60 seconds)
= 8 / 1800
= 0.0044 cm/s
_____________________________

Average velocity and average speed between 6 am to 6:30 pm is same as that of 6 am to 6:30 am

Answer 2

Answer:

Length of minute hand r=4 cm

In 30 minutes, the tip of minute hand reaches diametrically opposite end of the clock.

Thus displacement of tip of minute hand d=2r=8 cm

Time taken t=30 min=30×60=1800 s

So, average velocity v

avg

=

t

d

=

1800

8 cm

=0.0044 cm/s