Abob of mass of 0.18 kilograms is released from a height of 45 meters above the ground level. what is the value of the kinetic energy gained by the bob at the ground level? 250 joules 51 joules 79 joules 8.1 joules

We can assume that all gravitational potential energy is converted into kinetic energy of the object.

Hence, GPE = KE

Where GPE is gravitational Potential Energy (J) and KE is Kinetic Energy (J)

GPE = mgh

Where, m is the mass of the object (kg), g is acceleration due to gravity (9.8 m s⁻²) and h is the height to the object from ground (m).

m = 0.18 kg
g = 9.8 m s⁻²
h = 45 m

Hence, 
       GPE = 0.18 kg x 9.8 m s⁻² x 45 m
                = 79.38 J
                ≈ 79 J

Hence, KE = GPE = 79 J

Hence, the answer is '79 joules'.

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they are all solids.