Question

A sphere of diameter 0.2 m and mass 2 kg is rolling on an inclined plane with velocity v = 0.5 m/s. The kinetic energy of the sphere is :

• A. 0.4 J
• B. 0.3 J
• C. 0.6 J
• D. 0.42 J

Answer 1

The correct option is D 0.42 J

Kinetic Energy of sphere = Translational kinetic energy + Rotational kinetic energy

$=\frac{1}{2}m{v}^2+\frac{1}{2}I{\omega }^2$

$=\frac{1}{2}\times 2\times (0.5{)}^2+\frac{1}{2}\times \frac{2}{3}m{r}^2\times \frac{(0.5{)}^2}{(0.1{)}^2}$

$=0.25+0.17J$

$=0.42J$