An Object of mass 0.5kg is whirled at the end of string 0.8m long. If the strings makes three revolutions in 1.2sec, find the tension in the string.

98.00 98.2...N

98.2 n

To find the tension in the string, we can use the formula for centripetal force:

Tension = (mass x velocity^2) / radius

First, we need to find the velocity of the object. Since it make three revolutions in 1.2 seconds, we can calculate the angular velocity (ω) using the formula:

ω = (2π x number of revolutions) / time

ω = (2π x 3) / 1.2
= 15π / 6

Next, we can find the linear velocity (v) using the formula:

v = angular velocity x radius

v = (15π / 6) x 0.8
= 4π m/s

Now, we can calculate the tension in the string:

Tension = (mass x velocity^2) / radius
= (0.5 x (4π)^2) / 0.8
= (0.5 x 16π^2) / 0.8
= 32π^2 / 0.8
= 40π^2

Therefore, the tension in the string is 40π^2 Newtons.