A solid sphere of mass 1 kg rolls on a table with linear speed 2 m/s. Find its total kinetic energy.

Explanation

Data : M = 1 kg, v = 2 m/s
The total kinetic energy of a rolling body,
` E = 1/2 Mv^(2) (1 + k^(2)/R^(2))`
For a solid sphere, `k^(2) = 2/5 R^(2)`
` :. E = 1/2 Mv^(2)(1 + (2/5 R^(2))/R^(2)) = 1/2 Mv^(2) (1 + 2/5)`
` = 1/2 xx 7/5 Mv^(2) = 7/10 Mv^(2)`
` = 7/10 xx 1 xx 2^(2)`
` = (7 xx 4 )/10 = 2. 8 ` J