The average time that it takes for the car to travel the first 0.25m is 2.23 s
The average time that it takes for the car to travel the first 0.25 m is given by:
The average time to travel just between 0.25 m and 0.50 m is 0.90 s
First of all, we need to calculate the time the car takes in each trial to travel between 0.25 m and 0.50 m:
Then, the average time can be calculated as
Given the time taken to travel the second 0.25 m section, the velocity would be 0.28 m/s
The velocity of the car while travelling the second 0.25 m section is equal to the distance covered (0.25 m) divided by the average time (0.90 s):
The force of gravity is equal to the mass times centripetal acceleration.
Fg = m v^2 / r
The force of gravity is defined by Newton's law of universal gravitation as:
Fg = mMG / r^2
Therefore:
mMG / r^2 = m v^2 / r
MG / r = v^2
v increases as r decreases. So the planet with the smallest orbit (closest to the sun) will have the highest orbital velocity. Of the four options, that's Mercury.
Your answer would be D- Knowledge of the environment.
I hope this helped... ;)
1) Acceleration: 
The motion of the plane is a uniformly accelerated motion, so we can find its acceleration by using the suvat equation
where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the displacement
Here we have
v = 150 m/s is the final velocity of the plane
u = 0 (it starts from rest)
a=?
s = 1500 m is the displacement
Solving for a, we find
2. Time: 20 s
For this part of the problem, we can use another suvat equation:
v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
Here we already know:
v = 150 m/s is the final velocity of the plane
u = 0 (it starts from rest)
(found in part 1)
Solving for t, we find the time taken for the plane to reach the final velocity of 150 m/s:
