Question

An object is thrown from the ground with a velocity of 5 m/s.  If the object has a mass of 2kg, what will be its potential energy at the top-most point of its trajectory? (Assume g = 10 m/s^2)

(a) 5 J

(b) 15 J

(c) 25 J

(d) 50 J

I have been asked this question in an international level competition.

Question is from Potential Energy topic in portion Work, Energy and Power of Physics – Class 11

Answer 1

Right answer is (c) 25 J

For explanation I would say: Maximum height reached by the object;

h = v^2/(2 x g)

 = 25/20

 = 1.25 m

PE = m x g x h

 = 2 x 10 x 1.25

 = 25 J.