Question

a book with a mass of 1.8 kg sits on a bookshelf. if it has a gravitational potential energy of 42 J, how high is the Shelf? The acceleration of the gravity is 9.8 m/s^2. A) 2.1 B) 2.4 C) 1.6 D) 0.9

Answer 1

Answer:

23 m

Explanation:

h = 42 J/1.8 kg = 23 m

Answer 2

The shelf is 2.4 m high.

What is the height of the shelf?

PE = mgh where m is the mass, g is gravity, and h is the height from which the object can potentially fall. We are given enough info here to solve for h. Filling in:

42 = 1.8(9.8)h and

and rounding to 2 sig fig's as we need:

h = 42 / (1.8)(9.8)

h = 2.4 m

The formula for potential energy depends on the force acting on the two objects. For the gravitational force, the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters.

Learn more about gravitational force here: https://brainly.com/question/13010127

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