superman is flying 54.5m/s when he sees a train about to fall into the river 850m away. He must reach the train in 4.22s. What acceleration does he need?
+33654 Use the constant acceleration, kinematic equation s = ut +(1/2)at2 where u = initial velocity, t = time taken, s = distance and a = acceleration.
Rearrange to get: a = 2(s - ut)/t2
a = 2(850 - 54.5*4.22)/4.222 m/s2
a=2×(850−54.5×4.22)4.222⇒a=69.6311852833494306
acceleration ≈ 69.63 m/s2
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+33654 Use the constant acceleration, kinematic equation s = ut +(1/2)at2 where u = initial velocity, t = time taken, s = distance and a = acceleration.
Rearrange to get: a = 2(s - ut)/t2
a = 2(850 - 54.5*4.22)/4.222 m/s2
a=2×(850−54.5×4.22)4.222⇒a=69.6311852833494306
acceleration ≈ 69.63 m/s2
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