Work Energy And Power Question 206
Question: A load hangs from a travelling crane, moving horizontally with velocity v. If the load is not to swing more than 4 m horizontally, when the crane is stopped suddenly, what is the maximum allowable speed of the crane?
Options:
A) 4.05 m/s
B) 4.00 m/s
C) 3.00 m/s
D) 3.50 m/s
Show Answer
Answer:
Correct Answer: A
Solution:
[a] $ y=10-\sqrt{10^{2}-4^{2}}=0.84m $
Thus $ \frac{1}{2}mv^{2}=mgy $
Or $ v=\sqrt{2gy}=\sqrt{2\times 9.8\times 0.84} $
$ =4.05m/s. $
