Answer to Question #5361 in Mechanics | Relativity for Mario

Question #5361
A 121 kg physics professor has fallen into the Grand Canyon. Luckily, he managed to grab a branch and is now hanging 73 m below the rim. A student (majoring in linguistics and physics) decides to perform a rescue/experiment using a nearby horse. After lowering a rope to her fallen hero and attaching the other end to the horse, the student measures how long it takes for the horse to pull the fallen physicist to the rim of the Grand Canyon. The acceleration of gravity is 9.8 m/s^2.
If the horse’s output power is truly 1 horsepower (746 W), and no energy is lost to friction, how long should the process take?
Answer in units of s
1
Expert's answer
2011-12-01T08:11:06-0500
Let's make some denotations:
M = 121 kg;
H = 73 m ;
P = 746 W;
g = 9.8 m/s²;

The work necessary to pick the professor up is
A = mgH = 121*9.8*73 = 86563.4 J.
So, it will take
T = A/P = 86563.4/746 = 116.037 s.

Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

Comments

No comments. Be the first!

Leave a comment

LATEST TUTORIALS
New on Blog
APPROVED BY CLIENTS