A solid sphere of mass 2 kg rolls up a `30^(@)` incline with an initial speed of `10 ms^(-1)`. The maximum height reached by the sphere is `(g = 10 ms^(-2))`

Options

A. 3.5 m
B. 7 m
C. 10.5 m
D. 14 m

Answer

B

Explanation

In case of pure rolling, `(K_(R))/(K_(T))=(2)/(5)`
`:.` Total kinetic energy `= 7//5` times the translational kinetic energy. At highest point, whole of the kinetic energy will be convered into potential energy
`:. mgh=(7)/(5)((1)/(2)mv^(2))or h=(7v^(2))/(10g)=(7(10)^(2))/(10g)=(7(10)^(2))/(10xx10)=7m`