Question

A student has 474 J of gravitational energy while standing on a stool 0.84 m above the ground. The mass of the student is: a) 40 kg (to two significant digits) b) 58 kg c) 48kg d) 60 kg (to two significant digits)

Answer 1

b) 58 kg

Step-by-step explanation:

Gravitational potential energy is the energy that an object has due to its state or position in which it rests.

Gravitational potential energy = U = mass x gravity x height = m g h = 474 J

Height of the stool = h = 0.84 m

rearranging m g h and solving for the mass m gives m =

474 / (9.8)(0.84) = 57.6 kg = 58 kg (rounded to 2 significant digits).