Gravitation Question 120
Question: A body of mass m rises to height h = R/5 from the earth’s surface, where R is earth’s radius. If g is acceleration due to gravity at earth’s surface, the increase in potential energy is [CPMT 1989; SCRA 1996; DPMT 2001]
Options:
A) mgh
B) $ [\frac{4}{5}mgh] $
C) $ [\frac{5}{6}mgh] $
D) $ [\frac{6}{7}mgh] $
Show Answer
Answer:
Correct Answer: C
Solution:
$ [\Delta U=\frac{mgh}{1+h/R}] $ Substituting $ [R=5h] $ we get $ [\Delta U=\frac{mgh}{1+1/5}=\frac{5}{6}mgh] $
