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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?

 May 16, 2015

Best Answer 

 #1
avatar+33654 
+5

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)/4.22m/s2

 

a=2×(85054.5×4.22)4.222a=69.6311852833494306

 

acceleration ≈ 69.63 m/s2

.

 May 16, 2015
 #1
avatar+33654 
+5
Best Answer

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)/4.22m/s2

 

a=2×(85054.5×4.22)4.222a=69.6311852833494306

 

acceleration ≈ 69.63 m/s2

.

Alan May 16, 2015

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