Answer: if the heat energy is wasted, then, energy is lost forever.
Explanation: According to conservative of energy, which state that energy is neither created nor destroyed but only convert from one form to another.
The energy which should have been used in one form has been converted to heat energy which could have been used for for thing or the other, if there is nothing the heat energy can be used for, then the energy is wasted. This is tantamount to being lost forever.
Which body is in equilibrium?
(1) a satellite orbiting Earth in a circular orbit
. No. The forces on it are unbalanced. There's only one force acting on it ... the force of gravity, pulling it toward the center of the Earth. That's a centripetal force, and the satellite is experiencing centripetal acceleration.
(2) a ball falling freely toward the surface of Earth. No. The forces on it are unbalanced. There's only one force acting on it ... the force of gravity, pulling it toward the center of the Earth. The ball is accelerating toward the ground.
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(3) a car moving with a constant speed along a straight, level road. YES.</em> We don't even need to analyze the forces, just look at the car. It's moving in a straight line, and its speed is not changing. The car's acceleration is zero ! That right there tells us that the NET force ... the sum of all forces acting on the car ... is zero. THAT's called 'equilibrium'.
(4) a projectile at the highest point in its trajectory. No. The forces on it are unbalanced. There's only one force acting on it ... the force of gravity, pulling it toward the center of the Earth. The projectile is accelerating toward the ground.
Answer:
Part 1)

Part 2)

Part 3)

Part 4)

Part 5)

Explanation:
Part a)
Initial angular momentum of the merry go round is given as

here we know that


now we have


Part b)
Angular momentum of the person is given as

so we have


R = 1.99 m
so we have


Part 3)
Angular momentum of the person is always constant with respect to the axis of disc
so it is given as

Part 4)
By angular momentum conservation of the system we will have




Part 5)
Force required to hold the person is centripetal force which act towards the center
so we will have



All except C, feelings are not physical.
Particles transfer energy physically from one to the other either horizontally in a longitudinal wave, vertically in a transverse wave, or in circles in a surface wave. Waves can also be electromagnetic, which are always transverse and do not require a medium to propagate, like light waves traveling through space.