Given that,
Mass of the stone, m = 400 g = 0.4 kg
Initial speed, u = 20 m/s
It is climbed to a height of 12 m.
To find,
The work done by the resistance force.
Solution,
Let v is the final speed. It can be calculated by using the conservation of energy.

Work done is equal to the change in kinetic energy. It can be given as follows :

So, the required work done is 32.99 J.
Answer:
The mass of the second person is 28.91 kg
Explanation:
Given;
mass of the first adult, m₁ = 54.2 kg
distance of the first adult from the point of balance, x = 1.20 m
mass of the second adult, = m₂
distance of the second adult from the point of balance, y = 2.25 m
Taking moment about the point of balance, we will have
m₁x = m₂y
54.2 x 1.2 = 2.25y
2.25y = 65.04
y = 65.04/2.25
y = 28.91 kg
Therefore, the mass of the second person is 28.91 kg
Answer:
Short circuit, closed circuit, open circuit