OnlineCBT
Physics · WORK, ENERGY AND POWER
हिन्दीRefer to the figure showing a bob of mass \( m \) suspended by a light string of length \( L \) undergoing circular motion in a vertical plane. When the bob reaches point \( B \) at the horizontal level, the magnitude of its total acceleration is:
Correct answer · Option 1
\( \sqrt{10}g \)
Explanation
At point B, the speed is \( v_B = \sqrt{3gL} \). The centripetal acceleration is \( a_c = \frac{v_B^2}{L} = 3g \) (directed horizontally). The tangential acceleration is \( a_t = g \) (directed vertically downward). Total acceleration \( a = \sqrt{a_c^2 + a_t^2} = \sqrt{(3g)^2 + g^2} = \sqrt{10}g \).
