Laws of motion chain problem

Question

A bucket full of water is revolved in vertical circle of radius 5m. What should be the minimum speed at highest point do that the water does not fall off the bucket?

1. 2m/s 2. 3m/s 3. 7m/s 4. 4m/s

Answer 1

Minimum speed of bucket is =  (Rg)^1/2

^{Where R is radius}

^{g is acceleration due to gravity} 

^{So answer is (c)} 

Comments

You have just written the answer pls also explain