An object of mass 1.5 kg rests on a shelf where it has a gravitational potential energy of 7 joules. an object of mass 4.5 kg is placed on the same shelf. what is the gravitational potential energy of this second object? a. 7 joules b. 10 joules c. 21 joules d. 31.5 joules

C. 21 Joules

Explanation:

We apply the formula to calculate the potential energy (Ep):

Ep=m*g*h

Where:

Ep : potential energy in Joules (J)

m :mass in kilograms (kg)

g  acceleration due to gravity  (m/s²)

h: height in meters (m)

Calculation of the height (h)

Ep = m*g*h

7 = (1.5 )*(9.8) *(h )

7 = (14.7) (h )

h = 7 /  (14.7)

h= 0.476 m

Gravitational potential energy of the second object

Ep = m*g*h

Ep = (4.5 )*(9.8) *(0.476 )

Ep = (4.5 )*(9.8) *(0.476 )

Ep = 21 J

2b2t

explanation:

2b2t

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force