Answer:
I think frequency not sure though
How frequently a wave or vibration occurs during a span of time, determines the waves frequency. Frequency is the number of waves per unit time. The unit for frequency if a Hertz ( 1/second). The speed a wave travels is the wavelength multiplied by this frequency. The amplitude of a wave is the maximum distance the wave is displaced.
B the energy of the car. Sorry if this is not right
The value of the underlined 8 is, hundred billion's. Hope this helped!
While skydiving, its not just freely falling under Earth's gravity. Additional force called drag acts against the gravity which slows down the rate of fall. Drag is caused by the air molecules which pushes against the body as it falls through them. This is actually a significant amount of force which slows down the rate of fall of the body. Drag depends on the contact surface area and weight. More the surface area in contact, more would be the drag. The sitting position of the skydiver would experience less drag than the chest down position because of the less contact surface area of the body with the air molecules while in the former case. No two persons have identical body shape and weight. Hence, the rate of fall can be made nearly equal but not exactly equal. This is would be possible when they are having same body position.