Question

An 8.0-kg history textbook is placed on a 1.25-m high desk. How large is the gravitational potential energy of the textbook-Earth system relative to the desktop?

Answer 1

Gravitational potential energy of the textbook-Earth system relative to the desk = 98 N/m

Step-by-step explanation

Given that,

Mass of history book = 8kg

height of book from ground = 1.25m

acceleration due to gravity = 9.8m/s²

gravitational potential energy formula

GPE = Fg⋅h

GPE = mgh

where ,

m = mass of object(book)

g = acceleration due to gravity

h = the altitude of the object.

GPE = 8(9.8)(1.25)

= 98 N/m

So, gravitational potential energy of the textbook-Earth system relative to the desk = 98 N/m

Answer 2

Answer: 98 J

Explanation: The energy possessed by a body due to its placement in gravitational field. It is given by:

G.P.E. = m g h

m is the mass of the object, g is the acceleration due to gravity and h is the height.

mass of the book, m = 8.0 kg

height of the desk on which book is kept, h = 1.25 m

acceleration due to gravity, g = 9.8 m/s²

G.P.E = 8.0 kg × 9.8 m/s² × 1.25 m = 98 J.