Work Energy And Power Question 259
Question: In figure, a block having a mass of 5 kg is released from rest, where the spring acting on the body are horizontal and have a tension of 50 N. The force constant of each spring is, $ k=500N/m $ . The velocity of the block after it has descended by 0.3m.
Options:
A) 0
B) I m/s
C) 2 m/s
D) none
Show Answer
Answer:
Correct Answer: A
Solution:
[a] $ x _{i}=\frac{50}{500}=0.lm{\ell _{i}}=0.4-0.1=0.3m $
$ x _{f} =\sqrt{{{0.4}^{2}}- 0.3^{2}} -0.3= 0.2m $
$ 2\times \frac{1}{2}kx_i^{2}+mg\times 0.3=2\times \frac{1}{2}kx^2 _{f}+\frac{1}{2}mv^{2}\Rightarrow v=0 $
