Q.

A hollow spherical ball of uniform density rolls up a curved surface with an initial velocity 3 m/s (as shown in figure). Maximum height with respect to the initial position covered by it will be ________ cm (take g = 10 m/s2)             [2023]


Ans.

(75)

At highest point KEf=0

Initial KE=Translational KE+Rotational KE

                   =12mv2+12Iω2

In case of rolling v=Rω

                   =12mv2+12×23mR2×v2R2=56mv2

Apply energy conservation, KEi+PEi=KEf+PEf

            56mv2=mgh

h=56×10×9 m=1520m=75 cm