Question
Physics Question on work, energy and power
In the given figure, the block of mass _m _is dropped from the point ‘ A ’. The expression for kinetic energy of block when it reaches point ‘ B ’ is
Fig.
A
21mgy02
B
21mgy2
C
mg(y - y0)
D
mgy0
Answer
mgy0
Explanation
Solution
The correct answer is (D) : mgy0
Loss is potential energy = gain in kinetic energy
– (mg(y – y 0) – mgy) = KE – 0
⇒ KE = mgy 0