Question

An object is allowed to roll down an inclined plane starting from rest (consider the object to be uniform and having same mass) then object having largest speed at the bottom of ground,

• A. solid sphere
• B. spherical sphere
• C. solid disk
• D. thin cylinder

Answer 1

The correct option is A solid sphere

After body reaches bottom

$\frac{1}{2}m{v}^2(1+\frac{k^2}{r^2})=mgh\Rightarrow v\propto {(1+\frac{k^2}{r^2})}^{-1/2}$

thus, body with highest $\frac{r^2}{k^2}$ has highest velocity. Thus, sphere has highest speed at ground .