Question

An object moves in uniform circular motion at 15 m/sec and takes 1 sec to go two revolutions. What is the radius of this circle?

Answer 1

`1.19` meters

Explanation:

Well, we first find the distance covered by the object.

Distance is defined by:

`d=vt`

• `v` is the velocity of the object

• `t` is the time

And so,

`d=(15 \ "m")/(color(red)cancelcolor(black)"s")*1color(red)cancelcolor(black)"s"=15 \ "m"`

Since two revolutions are covered per second, so one revolution covers `(15 \ "m")/2=7.5 \ "m"`.

We can then say that the circumference of the circle is `7.5 \ "m"`.

Circumference is given by:

`C=2pir`

• `r` is the radius of the circle

So, the radius of the circle is:

`r=C/(2pi)=(7.5 \ "m")/(2pi)=1.19 \ "m"`