To solve this problem we will apply the linear motion kinematic equations. From the definition of the final velocity, as the sum between the initial velocity and the product between the acceleration (gravity) by time, we will find the final velocity. From the second law of kinematics, we will find the vertical position traveled.

Here,
v = Final velocity
= Initial velocity
g = Acceleration due to gravity
t = Time
At t = 4s, v = -30m/s (Downward)
Therefore the initial velocity will be


Now the position can be calculated as,

When it has the ground, y=0 and the time is t=4s,


Therefore the cliff was initially to 41.6m from the ground
The scientist is likely to be studying kinematics.
Kinematics is the branch of science, specifically physics, which is concerned with the motion of objects without reference to the forces that induce this motion. An example of kinematics is studying the change in velocity of an object over time or the distance covered by an object in a specified amount of time.
The correct answer is D. the star is getting farther away.
When the light has red-shifted, it shows that everything is moving away from a certain point. This is known as the Doppler effect and proves the Big Bang (which would be the center point that everything is moving away from). Just as a 'for your information', blue shift is when the star is moving towards us.
Hope I helped :)