Answer:
There are two reasons why air pressure decreases as altitude increases: density and depth of the atmosphere. Most gas molecules in the atmosphere are pulled close to Earth's surface by gravity, so gas particles are denser near the surface.
Explanation:
Answer:
Federal Role in Education is primarily a State and local responsibility in the United States. It is States and communities, as well as public and private organizations of all kinds, that establish schools and colleges, develop curricula, and determine requirements for enrollment and graduation.
Explanation:
The Role of Public Education in Supporting American Democracy. Since the founding of public education in the United States, public schools have been charged not only with giving future workers skills for the private marketplace, but also with preparing students to be citizens in a democracy.
Answer:
0.25 m
Explanation:
Refraction occurs when the velocity or wavelength of a wave changes at the interface between two media.
We know that refractive index=
Wavelength in medium A/wavelength in medium B = velocity in medium A/velocity in medium B
Let the wavelength of medium B be a
0.5/a = 0.3/0.15
0.5 × 0.15 = 0.3 × a
a= 0.5 × 0.15/0.3
a= 0.25 m
When using a simple machine, the benefit of using less force to lift an object is offset by the need to push for a larger distance so that energy can be conserved.
<u>Explanation:
</u>
A simple machine utilized for completing the works easily. So in order for easy and quick completion of works, these machines may increase the amount of force acting on the object by increasing the velocity or speed of the machine. As velocity term is present so the machines may also change the directions of force acting on the object of concern to do the work soon just like pulley.
Also other way of completing the work with less input force requirement is by increasing the distance or area of action for the force acting on it. As work done is a measure of acting force on a region multiplied with the displacement occurred with that force.
It can be known that force seems to be inversely proportional to distance or area of action. So if we need to use less force to lift an object, it is offset by the need to push for a larger distance in order to conserve the energy.
Answer : Radius of Earth is 6,340 Km.
Explanation
It is given that,
Tangential velocity of Earth at the equator, v = 465 m/s
Centripetal acceleration at the equation is, 
We know that the relation between centripetal acceleration and tangential velocity is :
..........(1)
Where,
v is tangential velocity
r is the radius
Putting all values in equation (1)
or
The Earth's radius is 6,340 Km. Hence, this is the required solution.
