1.) A stone falls from rest from the top of a cliff. A second stone is thrown downward from the
same height 2.2 s later with an initial speed of
43.12 m/s. They hit the ground at the same
time.
How long does it take the first stone to hit
the ground? The acceleration of gravity is
9.8 m/s^2.
Answer in units of s.

Answer for the first question is 3.3s. I just need the second one.

2.) How high is the cliff?
Answer in units of m

Air enters a gas turbine with two stages of compression and two stages of expansion at 100 kpa and 17°c. this system uses a regenerator as well as reheating and intercooling – the intercooler returns the air to the inlet temperature. the pressure ratio across each compressor is 4 ; 300 kj/kg of heat are added to the air in each combustion chamber; and the regenerator operates perfectly while increasing the temperature of the cold air by 20°c. determine the system’s thermal efficiency. assume isentropic operations for all compressor and the turbine stages and use constant specific heats at room temperature. (0.378)

If a star is moving toward earth, it is

According to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does maria's voyage take according to samir?