# The tension in a 2 m length of string that whirls a 1 kg mass at 4 m/s in a horizontal circle is calculated to be 8 N. How do you alculate the tension for the following case: twice the length of string?

Nov 24, 2015

The tension will be $4 \text{N}$

#### Explanation:

The tension is equal to the centripetal force given by:

$F = \frac{m {v}^{2}}{r}$

You can see that doubling $r$ will therefore half the tension to $4 \text{N}$

Check:

$F = \frac{1 \times {4}^{2}}{4} = 4 \text{N}$