The decrease in gravitational potential energy of the system is given by
where
m is the mass, g is the gravitational acceleration, and is the variation of height of the system.
also corresponds to the weight of the diver, therefore if we rearrange the equation and we use
and
, we can find her weight:
Answer:
the correct answer is c) 23 g
Explanation:
The heat lost by the runner has two parts: the heat absorbed by sweat in evaporation and the heat given off by the body
Q_lost = - Q_absorbed
The latent heat is
Q_absorbed = m L
The heat given by the body
Q_lost = M ΔT
where m is the mass of sweat and M is the mass of the body
m L = M c_{e} ΔT
m = M c_{e} ΔT / L
let's replace
m = 90 3.500 1.8 / 2.42 10⁶
m = 0.2343 kg
reduced to grams
m = 0.2342 kg (1000g / 1kg)
m = 23.42 g
the correct answer is c) 23 g
Answer: An 8 kg book at a height of 3 m has the most gravitational potential energy.
Explanation:
Gravitational potential energy is the product of mass of object, height of object and gravitational field.
So, formula to calculate gravitational potential energy is as follows.
U = mgh
where,
m = mass of object
g = gravitational field =
h = height of object
(A) m = 5 kg and h = 2m
Therefore, its gravitational potential energy is calculated as follows.
(B) m = 8 kg and h = 2 m
Therefore, its gravitational potential energy is calculated as follows.
(C) m = 8 kg and h = 3 m
Therefore, its gravitational potential energy is calculated as follows.
(D) m = 5 kg and h = 3 m
Therefore, its gravitational potential energy is calculated as follows.
Thus, we can conclude that an 8 kg book at a height of 3 m has the most gravitational potential energy.