Solve for r in Circular Motion Problem - Urgent Help Needed

Click For Summary
To determine the radius (r) for astronauts to weigh half of their Earth weight in a rotating space station moving at 42.7 m/s, the concept of artificial gravity through centripetal acceleration must be applied. The formula for centripetal acceleration is a = V^2/r, where V is the tangential velocity. To achieve half of Earth's gravity, the required centripetal acceleration should equal 0.5g (where g is the acceleration due to gravity on Earth). The correct approach involves setting the centripetal acceleration equal to 0.5g and solving for r, leading to the equation r = V^2/(0.5g). The initial solution was incorrect due to misunderstanding the nature of artificial gravity versus real gravity.
owura143
Messages
12
Reaction score
0
Urgent help needed, please! Circular motion

Suppose the surface (radius = r) of the space station is rotating at 42.7 m/s. What must be the value of r for the astronauts to weigh one-half of their Earth weight?


My soln: Let // represent square root

V = // (GMe/r)

I divided Me by 2 and made r the subject

r = GMe/V^2

but i got the anser wrong
 
Physics news on Phys.org
I presume the problem is talking about the artificial gravity created by a rotating space station--not real gravity. Hint: Consider centripetal acceleration.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

Replies
2
Views
2K
  • · Replies 14 ·
Replies
14
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
6
Views
4K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
5K
  • · Replies 20 ·
Replies
20
Views
5K