Question

A fishing reel resting on a shelf 5.00 m above the floor has a gravitational potential energy of 24.5 J with respect to the floor. The reel is now raised to another shelf that is 7.50 m above the floor. What is the new gravitational potential energy of the reel?
a. 4.90 J b. 9.81 J c. 73.5 J d. 36.8 J

Answer 1

Answer:

d. 36.8 J

Explanation:

Given parameters:

Height of the shelf = 5m

Gravitational potential energy  = 24.5J

New height  = 7.5m

Unknown:

New gravitational potential energy = ?

Solution:

The gravitational potential energy of a body is expressed as;

       Gravitational potential energy  = mgh

m is the mass

g is the acceleration due to gravity

h is the height

  Let us find the weight of the fishing reel;

            24.5 = mg x 5

            mg  = 4.9

 mg = weight of the reel

  Since we are using the same reel, weight will be the same;

New gravitational potential energy  = 4.9 x 7.5 = 36.75J

Approximately the new potential energy is 36.8J