Question

A body travels along a circular path of radius 70m. After travelling half revolution in 20
secs, find the a. Average velocity b. Average speed.​

Answer 1

Answer:-

Av = 11m/s

Av = 7m/s

Given :-

r = 70 m

Number of revolution = 1/2

Time taken = 20 s

To find :-

Average speed.

Average velocity.

Solution :-

Since, the body covers half revolution.

Therefore,

Distance travelled = circumference of semicircle

$S = \pi r$

→$S =\dfrac{22}{7}\times 70$

→$S = 22 \times 10$

→$S = 220 m$

Now,

$A_v = \dfrac {s}{t}$

→$A_v = \dfrac{220}{20}$

→$A_v = 11m/ s$

Displacement covered by body in half revolution = diameter of circle

$\vec{S} = 2r$

→$\vec{S} = 2 \times 70$

→$\vec{S} = 140 m$

$A_v = \dfrac{\vec{S}}{t}$

→$A_v = \dfrac{140}{20}$

→$A_v = 7m/ s$

hence, average speed of body will be 11 m/s

average speed of body will be 11 m/sAverage velocity will be 7m/s.

Answer 2

Answer:

Average speed=Distance/Time

=Semicircle/20

=πr/20

=220/20

=11 m/s

Average velocity=Dispacement/time

=diameter/20

=140/20

=7 m/s