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.
Answer:
Air drying
Explanation:
Sanitation is the set of measures that aims to preserve or modify the conditions of the environment in order to prevent diseases and promote health, improve the quality of life of the population and the productivity of the individual and facilitate economic activity. Basic sanitation is a right guaranteed by the Constitution as the set of services, infrastructure and operational installations for water supply, sanitary sewage, urban cleaning, urban drainage, solid waste and rainwater management.
Sanitation can be carried out in several ways, except for dry air, as this would damage the quality of sanitation and the environment.
Sanitation is important in treated water, sewage collection and treatment services lead to an improvement in the quality of people's lives, especially in child health, with a reduction in child mortality, improvements in education, in the expansion of tourism, in the valuation of properties, in income of the worker, in the cleaning of rivers and preservation of water resources, etc.
4
Just divide 12 by 3, so if it takes 3 seconds, then every second, it goes up 4.
Answer:
(C) 40m/s
Explanation:
Given;
spring constant of the catapult, k = 10,000 N/m
compression of the spring, x = 0.5 m
mass of the launched object, m = 1.56 kg
Apply the principle of conservation of energy;
Elastic potential energy of the catapult = kinetic energy of the target launched.
¹/₂kx² = ¹/₂mv²
where;
v is the target's velocity as it leaves the catapult
kx² = mv²
v² = kx² / m
v² = (10000 x 0.5²) / (1.56)
v² = 1602.56
v = √1602.56
v = 40.03 m/s
v ≅ 40 m/s
Therefore, the target's velocity as it leaves the spring is 40 m/s