Question

A small rubber ball of mass 13 g is swung in a horizontal circle with a period of 0.8 seconds. The length of the string attached to the ball is 20 cm. What is the tension in the string?

Answer 1

0.01625 N

Explanation:

Given:

mass = m = 13 g = 0.013 kg

period = p = 0.8 sec

length = L = 20 cm = 0.2 m

We have the following formula to calculate the tension in the string:

`p=\frac{2L}{\sqrt[]{\frac{T}{m\text{/L}}}}`

We solve for T:

`\begin{gathered} p^2=\frac{4L^2}{\frac{T}{m\text{/L}}} \\ p^2=(4L^2\cdot m)/(TL) \\ T=(4L\cdot m)/(p^2) \\ \text{ We replace} \\ T=(4\cdot0.2\cdot0.013)/(0.8^2) \\ T=0.01625\text{ N} \end{gathered}`

The tension in the string is 0.01625 N