Question

A ball of mass 10 gram is dropped from a height of hundred metre, after striking the ground 25% of kinetic energy decreases. how much height the ball will attend after striking the ground?​

Answer 1

Answer:

A ball of mass 10 gram is dropped from a height of hundred metre, after striking the ground 25% of kinetic energy decreases. how much height the ball will attend after striking the ground?

75metre

Answer 2

Given,

• M = 10g = 0.01kg
• h = 100m
• After striking the ground 25% of kinetic energy decreases.

To Find,

• How much height the ball will attend after striking the ground?

Solution,

$\begin{gathered} →Kinetic \: \: Energy = Mgh \: \: (g = 10m {s}^{ - 2} ) \\ \\ →Kinetic \: \: Energy = 0.01kg \times 10m {s}^{ - 2} \times 100m \\ \\→ Kinetic \: \: Energy = 10J\end{gathered} l$

After striking the ground 25% of kinetic energy decreases.

So,

75% of Kinetic Energy remains

$\begin{gathered}→ 75 \: percent \: \: of \: \: 10J \\ \\ → \frac{75}{100} \times 10J \\ \\→ 7.5J\end{gathered}$

Required Answer,

$\begin{gathered}→Kinetic \: \: Energy = 7.5J \\ \\→ Mgh = 7.5J \\ \\ →0.01kg \times 10m {s}^{ - 2} \times h = 7.5J \\ \\→0.1kgm {s}^{ - 2} \times h = 7.5J \\ \\ →h = \frac{7.5J}{0.1kgm {s}^{ - 2} } \\ \\ → h = 75m\end{gathered}$

• Height = 75m