A car moving with a speed of 54km/h takes a turn of radius 20 m. A simple pendulum is suspended from the ceiling of the car. Determine the angle made by the string of the pendulum with the vertical during the turning. (Take g=10m/s2)
(A)tan−1(0.5)
(B)tan−1(0.75)
(C)tan−1(1.125)✓ Correct
(D)tan−1(0.25)
Answer: (C)
Solution
Converting the speed, v=54×185=15m/s. As the car turns, the bob settles where the horizontal component of the string tension supplies the centripetal force while the vertical component balances gravity, so tanθ=rgv2. Substituting, tanθ=20×10152=200225=1.125. The string makes an angle tan−1(1.125) with the vertical.
JEE Main · 2026 · 08 Apr 2026 · Shift 2 · Single correct option