Need Help with Centripetal Force & Gravitation Problems?

In summary, the conversation is about a person looking for help with an assignment on centripetal force and gravitation problems. They are asking for answers and explanations for different parts of the assignment, specifically for questions 4 and 5. The person sharing their answers also asked for clarification on question 5 and made a correction to their previous answer for question 4. The conversation ends with the correct answer to question 5 being determined and the person thanking the other for their help.
  • #1
harmeet_angel
26
0
it's on centripetal force and gravitation problems..
wonderin if anyone can provide me answers such that i can compare mine
here's the assignment
http://www.geocities.com/cheemaharmeet/assignment.jpg

mine are {
1. 8N;
2. 1.97 hr;
3. 7.9E3 m/s
4. 382.26 m, 5.49E3 N
5. 8E-10 N
6. 2.93E41 kg}
I would really thankful, is someone can provide me answers..
and if u can do atleast.. please try #5.. i am confused over that.because my book also have answer to that question, and mine one's different from that
 
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  • #2
I don't get the same answer for #4. Can you show more of how you got it? Perhaps I made an error...

Regarding #5, what is the answer the book gives? I think I know why you got a different answer.
 
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  • #3
hage567 said:
I get the same answers as you on all questions except #4. Can you show more of how you got it? Perhaps I made an error...

thnx a lot for assuring me..
and for #4

N-W = centripetal force
m.(normal a)-mg = m(v^2/r)

but normal a=7g

so
(v^2/r)=7g-g

so r=(v^2/g)
=382.23 m

and
N = 7 x 9.81 x 80 kg


I think i am wrong, perhaps because in the question it says "acceleration of the pilot"..
so that means net acceleration?
 
  • #4
Note that I edited my first post about question #5. Can you tell me what the book's answer is?
 
  • #5
hage567 said:
Note that I edited my first post about question #5. Can you tell me what the book's answer is?

6.8 N
umm.. i think this isn't possible though
 
  • #6
(v^2/r)=7g-g

so r=(v^2/g)
=382.23 m

Even if you do it this way, shouldn't it be 6g on the bottom (7g-g=6g)?

The wording is bit confusing in the question. I would think they are just asking for the acceleration, so then r = (v^2)/7g.
To find the force of the seat on the pilot, you just sum the forces up, so N - mg = mv^2/r. That's the approach I would take, but you decide what you want to do.
 
  • #7
oops, that was a typo
umm.. yea, i think your way''s right
 
  • #8
harmeet_angel said:
6.8 N
umm.. i think this isn't possible though

Is that supposed to be 6.8x10^-10 N though? Gravitational force is a vector. So for the third mass (4kg), you need to break up the force into its x and y components. Then do a sum of the forces in each direction. Then find the resultant of those two. Does that make sense? If you do that, you should get the answer the book gives.
 
  • #9
Yes 6.8x10^-10 N is the correct answer for 5/.

Regards.

Nacer.
 

FAQ: Need Help with Centripetal Force & Gravitation Problems?

1. What is centripetal force and how does it relate to gravitation?

Centripetal force is the force that acts on an object moving in a circular path, directed towards the center of the circle. It is the force that keeps an object in circular motion. Gravitation is the force of attraction between two objects with mass. Centripetal force is related to gravitation because, in circular motion, the centripetal force is provided by the gravitational force between the two objects.

2. How is centripetal force calculated?

Centripetal force can be calculated using the formula Fc = (mv^2)/r, where Fc is the centripetal force, m is the mass of the object, v is the velocity, and r is the radius of the circular path. This formula is derived from Newton's second law, which states that force is equal to mass times acceleration (F=ma). In this case, the acceleration is the centripetal acceleration, which is equal to v^2/r.

3. Can centripetal force be greater than gravitational force?

Yes, centripetal force can be greater than gravitational force. This is because centripetal force is dependent on the mass, velocity, and radius of the object, whereas gravitational force is only dependent on the masses of the two objects and the distance between them. If the object is moving at a high velocity or has a smaller radius, the centripetal force will be greater than the gravitational force.

4. What is the difference between centripetal force and centrifugal force?

Centripetal force acts towards the center of the circular path, while centrifugal force acts outward from the center. Centrifugal force is often referred to as a "fictitious force" because it only appears to exist due to the object's inertia. In reality, the object's inertia causes it to continue moving in a straight line, while the centripetal force acts to change its direction towards the center of the circle.

5. How does centripetal force affect the motion of objects in outer space?

In outer space, there is no air resistance or other external forces, so centripetal force plays a crucial role in keeping objects in orbit. The centripetal force between the object and the planet or star it is orbiting is what keeps it in its circular path. If the centripetal force is not equal to the gravitational force, the object may either escape the orbit or be pulled towards the central object.

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