Answer: D.) 39,200 J
Via the equation of potential energy PE = mgh where m is mass, g is the average gravity on earth and h is the height. In this case m = 400 kg, g = 9.8, h = 10 m thus:

P.E.= 39,200 Joules
Actually, the speed of the earth is the same everywhere, taking the angular speed as the valid measure of the speed
Average speed of the car is 11 m/s
Explanation:
- Speed is calculated by the rate of change of displacement.
- It is given by the formula, Speed = Distance/Time
- Here, distance = 2155 m and time = 195.9 s
Speed of the car = 2155/195.9 = 11 m/s
Answer:
The question is incomplete. However, I believe, it is asking for the acceleration of the elevator. This is 3.16 m/s².
Explanation:
By Hooke's law, 
F is the force on a spring, k is the spring constant and e is the extension or compression.
From the question,

This is the force on the mass suspended on the spring. Its acceleration, a, is given by



This acceleration is more than the acceleration due to gravity, g = 9.8 m/s². Hence the elevator must be moving up with an acceleration of
12.96 - 9.8 m/s² = 3.16 m/s²
Answer:
532 millimeters of mercury
Explanation:
In order to convert the pressure from atm to millimeters of mercury (mm Hg), we should remind the conversion factor between the two units:
1 atm = 760 mm Hg
Therefore, we can solve the problem by setting up the following proportion:

Solving for x, we find
