**Answer: A **7.8 ·10^22 J **B ** 1.6 times **C** 3.9 ·10^15 $

**Explanation: **A : Speed of light c = 3.0·10^8 m/s, 0.12·c = 3.6·10^7 m/s

Mass is 120·10^6 kg . Change of kinetic energy

E = ½mv² = 0.5 · 120·10^6 kg · (3.6·10^7 m/s)² = 7.776·10^22 J

B exponent is same , 7.776 / 5 = 1,55 times of energy use of Earth in year.

C Energy is 7.776·10^22 J / 10^6 = 7.776·10^16 MJ

Price is 0.05 $ · 7.776·10^16 MJ = 3.888·10^15 $

The power of the antenna is

and since the power is the emitted energy divided by the time, the energy emitted per second is

The frequency of the emitted photons is

So the energy of a single photon is

Therefore, to find the number of emitted photons per second, we should divide the total energy emitted by the antenna in 1 second by the energy of a single photon:

Answer:

0m/s²

Explanation:

A body with a constant speed always has a zero acceleration

Hence if Korey ran around the track at 10 meters per second and had a constant speed and did not change directions, then his acceleration will be 0m/s² not considering his initial speed