Work Energy And Power Question 327
Question: Block 1 and Block 2 are again released from $ h=1.2m. $ Block 1 flies off the track end at 30° and Block 2 at $ 45{}^\circ $ . Their speeds when they hit the floor 1 meter below the track end:
Options:
A) are smaller for Block 1 than Block 2.
B) are larger for Block 1 than Block 2.
C) are the same for Block 1 and Block 2.
D) depend on mass and angle, so the question cannot be answered.
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Since the speeds are the same at the track ends and they both fall through a vertical distance of 1 m from the track bottom, conservation of energy shows that their speeds when they strike the floor are equal also.
Assume h = 1m and v = 4.85 m/sec for both.
Then : $ 1/2mv^{2}+mgh=1/2mV^{2} $ (The mass will cancel, so V is the same for both blocks.)
