Answer:
The first part can be solved via conservation of energy.

For the second part,
the free body diagram of the car should be as follows:
- weight in the downwards direction
- normal force of the track to the car in the downwards direction
The total force should be equal to the centripetal force by Newton's Second Law.

where
because we are looking for the case where the car loses contact.

Now we know the minimum velocity that the car should have. Using the energy conservation found in the first part, we can calculate the minimum height.

Explanation:
The point that might confuse you in this question is the direction of the normal force at the top of the loop.
We usually use the normal force opposite to the weight. However, normal force is the force that the road exerts on us. Imagine that the car goes through the loop very very fast. Its tires will feel a great amount of normal force, if its velocity is quite high. By the same logic, if its velocity is too low, it might not feel a normal force at all, which means losing contact with the track.
(2.0 x 10² N/Coul) x (-1.6 x 10⁻¹⁹ Coul) = -3.2 x 10⁻¹⁷ N
The magnitude is 3.2 x 10⁻¹⁷ Newton.
Answer:
Accelerating charges.
Explanation:
Electromagnetic waves are waves produced by the vibration of both electrical and magnetic fields.
This interaction produces an energy source that does not require any medium to propagate.
To produce electromagnetic waves, electric and magnetic fields must be vibrating.
An electric charge produced when vibrating under voltage will produce electromagnetic waves. This is the same for all sources of these waves.
The sun produces electromagnetic waves. A lot of human activities also does this.
Answer:
an increase in gasses that absorb heat
Explanation:
Greenhouse effect refers to the gradual increase in the earth's temperature due to an increase in the concentration of certain gases in the atmosphere. These gases are called greenhouse gases and they include; water vapour, nitrogen 1 oxide, carbon IV oxide etc. Green house effect is said to occur when heat radiating outwards from the earth surface towards space is trapped close to the earth's surface due to the presence of greenhouse gases in the atmosphere.
Greenhouse effect leads to increase in the temperature of the earth, melting of polar ice caps and possibly flooding due to a rise in sea levels.
Greenhouse gases act as glass in a greenhouse. They allow heat to pass through onto the earth surface but trap the heat and prevent it from being radiated outwards back to space. Thereby increasing the surface temperature of the earth.