The three branches of science are life, earth, and physical science.
Life science deals with living organisms, so, biology is the most important of these sciences, although there are many.
Earth science deals with Planet Earth, studying its atmosphere, lithosphere, etc.
Physical science studies the inorganic world.
Answer:
a)
, b) 
Explanation:
a) The potential energy is:



b) Maximum final speed:

The final speed is:


It's 12.1 m/s, assuming that's the launch velocity that's given.
For projectile motion, velocity's y-component is parabolic/quadratic. It's x-component is constant, so you don't need to know it.
Answer:
This can be used to find out the speed of the returned journey. The equation means speed = returned distance ÷ time.
Explanation: