Question

In a popular daredevil trick to complete a vertical loop on a motorcycle, the rider falls off the track because of the less speed before reaching the top of the loop. Determine the minimum speed necessary for a rider to successfully go around a vertical loop of the radius $15meters$.

• A. $0.12m/s$
• B. $12.12cm/s$
• C. $121.2m/s$
• D. $12.12m/s$

Answer 1

The correct option is D

$12.12m/s$

To calculate the minimum necessary speed to complete the loop, rider's weight should get balanced with the centripetal force at the top of the loop. Then, we can write,

$mg$ = $\frac{mv²}{r}$

That leads to,
$g$ = $\frac{v²}{r}$

Therefore, v = $\sqrt{g\times r}$

$v$ = $\sqrt{9.8\times 15}$

$v=12.12m/s$