Newtons Law of Motion/Free Falling objct

AI Thread Summary
A user seeks verification of their calculations regarding a fireman sliding down a pole, starting from rest and landing at a speed of 4.9 m/s after falling 3.2 meters. They calculated the time of descent as 1.6 seconds and derived an average acceleration of -4 m/s². The user then applied Newton's second law to find the average force exerted on the fireman by the pole, resulting in a force of 534.5 N. They express uncertainty about their approach, suggesting they may have incorrectly calculated time before determining acceleration. The discussion highlights the importance of correctly applying physics principles in problem-solving.
baqi
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Hi I have a problem I need someone to check over and see if I have it right!

Thank you for trying in advance

Responding to an alarm, a 92kg fireman slides down a pole to the ground floor, 3.2m below. The fireman starts at rest and lands with a speed of 4.9 m/s. Find the average force exerted on the fireman by the pole.

m=92 Kg, d=3.2m, Vf= 4m/s
I found time first: (Can I do that?)
y-vector
y=0.5 (Voy+Vy)t
3.2m =0.5 (0+4m/s)t
t=1.6s

y=yo+Voyt+0.5ayt^2
ay=2(y-yo) / t^2
ay = (2)(0-3.2m) / 1.6s
ay=-4m/s^2

Sum of Fy= F-mg
F-mg=ma
F= may+mg = m(ay+g)
F = (92kg)(-4m/s^2+9.81m/s^2)
F= 534.5N
Thanks
 
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Compare the quantities given in the problem to the quantities inserted into the formulas. And watch for exponents.
 
thanks

I think how I solved the above question is wrong because I found time and then solved for accerlation instead of just finding accerlation from the information given and then account for all the forces...

And for the free falling object I forgot what I was going to ask...
 
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