A pendulum bob has a speed of 3 m/s at its lowest position. The pendulum is 50 cm long. The speed of bob, when the length makes an angle of 60 ° to the vertical will be (g = 10 m/s2) ____________ m/s. Numerical answer type. Work it out, then open the answer.

Answer: 2. Rise of bob at 60°: h = L(1 - cos 60°) = 0.5 × 0.5 = 0.25 m. v² = u² - 2gh = 9 - 2 × 10 × 0.25 v² = 4 v = 2 m/s

A pendulum bob has a speed of 3 m/s at its lowest position. The… | JEE Main 2021 (25 Jul, Shift 1)

Q25JEE Main 2021 · 25 JUL · SHIFT 1Medium

Conservation of Energy

A pendulum bob has a speed of 3 m/s at its lowest position. The pendulum is 50 cm long. The speed of bob, when the length makes an angle of 60 ${}^\circ$ to the vertical will be (g = 10 m/s2) ____________ m/s.

Numerical answer type. Work it out, then open the answer.

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Answer: 2

Rise of bob at $60^\circ$ : $h = L(1 - \cos 60^\circ) = 0.5 \times 0.5 = 0.25\text{ m}$ .
$v^2 = u^2 - 2gh = 9 - 2 \times 10 \times 0.25$
$v^2 = 4$
$v = 2\text{ m/s}$

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Conservation of Energy question from JEE Main 2021 (25 Jul, Shift 1)

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