Answer:

Explanation:
Given that,
Pressure, P = 1 atm = 101325 Pa
Area of the square surface, A = 10² = 100 m²
We need to find the mass of vertical column of air. We know that, pressure is equal to the force acting per unit area. So,

So, the required mass of the vertical column of air is
.
Answer:
B. 24.2 m/s
Explanation:
Given;
mass of the roller coaster, m = 450 kg
height of the roller coaster, h = 30 m
The maximum potential energy of the roller coaster due to its height is given by;



Therefore, the maximum speed of the roller coaster is 24.2 m/s.
Answer:
5.7 x 10^12 C
Explanation:
Let the charge on earth and moon is q.
mass of earth, Me = 5.972 x 10^24 kg
mass of moon, Mm = 7.35 x 10^22 kg
Let d be the distance between earth and moon.
the gravitational force between them is

The electrostatic force between them is

According to the question
1 % of Fg = Fe



q = 5.7 x 10^12 C
Thus, the charge on earth and the moon is 5.7 x 10^12 C.
Answer:
15.065ft
Explanation:
To solve this problem it is necessary to consider the aerodynamic concepts related to the Drag Force.
By definition the drag force is expressed as:

Where
is the density of the flow
V = Velocity
= Drag coefficient
A = Area
For a Car is defined the drag coefficient as 0.3, while the density of air in normal conditions is 1.21kg/m^3
For second Newton's Law the Force is also defined as,

Equating both equations we have:



Integrating


Here,






Replacing:



