Explanation:
a) The height of the ball h with respect to the reference line is
so its initial gravitational potential energy 
is
b) To find the speed of the ball at the reference point, let's use the conservation law of energy:
We know that the initial kinetic energy 
as well as its final gravitational potential energy 
are zero so we can write the conservation law as
Note that the mass gets cancelled out and then we solve for the velocity v as
The reason for people to swim easier in salt water than fresh water is because of buoyancy
Explanation:
In fresh water there is lack of minerals and has fresh water alone. The density of fresh water is 1000 kg/m³. Hence, in fresh water cannot exert the suitable buoyancy for the swimmer to float easier than that of salt water.
But in Salt water due to enrichment of salts and minerals it is found that salt water has more density than fresh water. Here the salt water offers more buoyancy to the swimmer to lift him up in the water surface and to swim faster and easier than fresh water.
It is similar to that egg floats in the salt water and sinks inside the fresh water because of its own body weight.
Since both heat and work can be measured and quantified, this is the same as saying that any change in the energy of a system must result in a corresponding change in the energy of the surroundings outside the system. In other words, energy cannot be created or destroyed.
Answer:
Sliding would be an uneven rhythm because Galloping and skipping has a constant flow of the same movement and same noise.
Explanation:
