- The hollow sphere reaches the bottom first.
- The solid sphere reaches the bottom with greater speed.
- The solid sphere reaches the bottom with greater kinetic energy.
- The two spheres will reach the bottom with same linear momentum.
The solid sphere reaches the bottom with greater speed.
Explanation:
Acceleration of a sphere on the incline plane is given by:
$\text{a}=\frac{\text{g}\sin\theta}{1+\frac{\text{I}_{\text{COM}}}{\text{mr}^2}}$
ICOM for a solid sphere $=\frac{2}{5}\text{mr}^2$
So, $\text{a}=\frac{\text{g}\sin\theta}{1+\frac{2\text{mr}^2}{5\text{mr}^2}}=\frac{5}{7}\text{g}\sin\theta$
ICOM for a hollow sphere $=\frac{2}{3}\text{mr}^2$
So, $\text{a}'=\frac{\text{g}\sin\theta}{1+\frac{2\text{mr}^2}{3\text{mr}^2}}=\frac{3}{5}\text{g}\sin\theta$
The acceleration of the solid sphere is greater; therefore, it will reach the bottom with greater speed.
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