Rotational MotionHard
Question
A point P moves in counter-clockwise direction on a circular path as shown in the figure. The movement of ′P′ is such that it sweeps out a length s = t3 + 5, where s is in metres and t is inseconds. The radius of the path is 20 m. The acceleration of ′P′when t = 2 s is nearly
Options
A.13 m/s2
B.12 m/s2
C.7.2 m/s2
D.14 m/s2
Solution
S = t3 + 5
∴ speed, v =
= 3t3
and rate of change of speed = = 6t
∴ tangential acceleration at t = 2s, at = 6 × 2 = 12 m/s2
at t = 2s, v = 3(2)2 = 12 m/s
∴ centripetal acceleration,
∴ net acceleration =
14 m/ s2
∴ speed, v =
= 3t3and rate of change of speed =
= 6t∴ tangential acceleration at t = 2s, at = 6 × 2 = 12 m/s2
at t = 2s, v = 3(2)2 = 12 m/s
∴ centripetal acceleration,
∴ net acceleration =
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