If a solid sphere of mass 1 kg and radius 0.1 m rolls without slipping at a uniform velocity of 1 m/s along a straight line on a horizontal floor, the kinetic energy is

Options

A. `(7)/(5) J`
B. `(2)/(5)J`
C. `(7)/(10)J`
D. 1 J

Answer

C

Explanation

K.E of rolling `=((1)/(2)mv^(2)+(1)/(2)I. (v^(2))/(R^(2)))`
`rArr K.E = (1)/(2)mv^(2)+(1)/(2).(2)/(5).(mr^(2).v^(2))/(r^(2))`
`K.E=(1)/(2)mv^(2)xx (7)/(5)`
`m = 1 kg " ", " " v = 1 m//s`
`K.E =(1)/(2)xx 1xx(7)/(5)=(7)/(10)J`