A type of material that tries to prevent the flow of thermal energy is called an insulator.
Answer:

Explanation:
Tarzan swing can be thought of as change in potential energy by going from higher location We solve for height of beginning of the swing by using simple cosine equation:
So

ΔE=mg(h₂-h₁)

The potential energy of Tarzan initial position is converted into kinetic energy of his swing.By using kinetic equation
Answer: I do
Explanation:
Resistance opposes current thereby reducing the amount of current that flows through a circuit. In other words, it leads to a loss of electrical energy.
Ideally speaking, a good circuit should have no internal resistance as this would lead to more energy having to be supplied to overcome that resistance. External resistance however, is not a bad thing. For instance, oxygen being removed from lightbulbs.
Explanation:
It is given that,
The volume of a right circular cylindrical, 
We know that the volume of the cylinder is given by :

............(1)
The upper area is given by :



For maximum area, differentiate above equation wrt r such that, we get :



r = 1.83 m
Dividing equation (1) with r such that,



Hence, this is the required solution.