Mechanical Energy Conservation

Question

A 2 kg block slides from height 5 m on frictionless track. Speed at bottom? (g = 10 m/s²)

RankGuru · Accepted Answer

1. **Conservation of Mechanical Energy**: In the absence of friction, $U_{initial} + K_{initial} = U_{final} + K_{final}$.
2. **Setup**: At the top, $K=0$. At the bottom, $U=0$ (ground reference).
3. **Equation**: $mgh = \frac{1}{2} mv^2$.
4. **Mass independence**: $v = \sqrt{2gh}$.
5. **Substitution**:
   - $v = \sqrt{2 	imes 10 	imes 5} = \sqrt{100}$
   - $v = 10$ m/s.
6. **Result**: The speed at the bottom is **$10$ m/s**.

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Mechanical Energy Conservation

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