My best guess is A There is missing a time unit in the question. I know that 4.4 *5 = 21 so that would be my best guess.
(a) Determine the circumference of the Earth through the equation,
C = 2πr
Substituting the known values,
C = 2π(1.50 x 10¹¹ m)
C = 9.424 x 10¹¹ m
Then, divide the answer by time which is given to a year which is equal to 31536000 s.
orbital speed = (9.424 x 10¹¹ m)/31536000 s
orbital speed = 29883.307 m/s
Hence, the orbital speed of the Earth is ~29883.307 m/s.
(b) The mass of the sun is ~1.9891 x 10³⁰ kg.
Answer:
kinetic energy + potential energy
Answer: it reduces dependence on fossil fuels. Disadvantage: it would emit pollution into the air.