Satellites and Space station questions

[F.B]

I really don't understand the universal gravitation chapters and the satellites one. It is sooo confusing. So can anyone help me with these questions.

1. Determine the magnitude of the apparent of a 56 kg student standing in an elevator when the elevator is experiencing an acceleration of (a) 3.2 m's^2 [down] and (b) 3.2 m/s^2 [Up].
I don't even know how to start this question. I don't even know what exactly they are looking for. So can anyone please help.

2. The ISS travels at an altitude of 450 km above the surface of the Earth.
(a) Determine the magnitude of the gravitational forces on a 64 kg astronaut at that altitude.
(b) What percentage of the astronauts Earths-bound weight is in the force in (a)?

I don't know how to start any of these questions. Can anyone please tell me step by step on how to do this please.

 

[Aneleh]

1. What do you feel happens when you are in an elevator and it moves up or down? Do you feel "lighter" or "heavier"? Start by drawing a free body diagram of the person with the acceleration due to the elevator and the acceleration due to the force of gravity. But it's not clear to me what exactly they are asking for, "the magnitude of the apparent" ?

2. a) Well you have the general equation for the Force of Gravity exerted on one mass by another, you just solve that.

 

[quicknote]

I understand that these concepts can be confusing at first, but with practice and a solid understanding of the principles, you will be able to solve these questions easily. Let me break down the concepts of satellites and universal gravitation for you and provide step-by-step instructions on how to solve the questions.

Firstly, let's talk about satellites. Satellites are objects that orbit around a larger object, such as a planet or a star. They are held in their orbit by the force of gravity, which is a universal force that exists between all objects with mass. This force is described by Newton's Law of Universal Gravitation, which states that the force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

Now, let's move on to the questions. For the first question, we are given the mass of a student and the acceleration of the elevator. We need to find the apparent weight of the student in both cases (when the elevator is accelerating downwards and upwards). To do this, we can use Newton's Second Law, which states that the force on an object is equal to its mass multiplied by its acceleration. So, for part (a), we can calculate the apparent weight as follows:

F = m*a
F = (56 kg)(3.2 m/s^2)
F = 179.2 N

This is the apparent weight of the student when the elevator is accelerating downwards. For part (b), we can use the same formula, but with a negative acceleration since the elevator is now moving upwards. So, the apparent weight would be:

F = m*a
F = (56 kg)(-3.2 m/s^2)
F = -179.2 N

This means that the student would feel a force of 179.2 N pushing them downwards, giving the sensation of being lighter. In both cases, we are simply using Newton's Second Law to calculate the force on the student due to the acceleration of the elevator.

Moving on to the second question, we are asked to determine the gravitational force on an astronaut in the International Space Station (ISS). To do this, we need to use the formula for gravitational force:

F = (G*m1*m2)/r^2

Where G is the universal gravitational constant, m1 and m2 are the masses of the two objects (in this case, the Earth and the astronaut),