Question

an insect moving on circular path of radius 5meter. if completes one round in 80seconds. calculate distance and displacement after 3minutes. (std-9 chapter 8 motion)​

Answer 1

Answer:

Explanation:

Given radius is 5 meter.

The path travelled by a body is known as Distance.

The shortest distance between initial and final point is known as Displacement

WE have to calculate the distance after 3 min

WE know that 1 minute = 60 seconds

so 3 min = 3*60=180 seconds

It takes 80 seconds to complete 1 round

then  how many seconds it takes to complete in 180 seconds?

that is 1  ------80 sec

           ? -----180 sec

we have  to cross multiply

180*1 = 80*?

?=180/80=2.25

So it completes 2 rounds completely and enters into 3rd round and completes 1/4 in third round

now 1 round is 5 meters

2 rounds = 5*2=10

1/4 = 1.25

so 2 1/4 = 10+1.25=11.25 meters

Displacement is shortest distance between initial and final points

as it covers 2 rounds completely displacement is 0

and we have 1/4th distance in 3rd rounds that comes to displacement which is 1.25 meters.

Finally distance is 11.25 meters

and displacement is 1.25 meters

If you have any doubt feel free to ask

Hope this will help you

Good Day..