Circular Motion of a moving rock Problem

In summary, the problem involves a person holding a bucket with a 480g rock inside and swinging it in a vertical circle with a diameter of 2.8m. The question is asking for the minimum speed the rock must have at the top of the circle to stay in contact with the bottom of the bucket. Using the equation N + mg = mv^2/r, the correct answer is found by setting N = 0 and solving for v with the correct radius of 1.4m, resulting in a minimum speed of 7.0 m/s.
  • #1
KrazySocoKid
11
1

Homework Statement


You hold a bucket in one hand. In the bucket is a 480g rock. You swing the bucket so the rock moves in a vertical circle 2.8m in diameter. What is the minimum speed the rock must have at the top of the circle if it is to always stay in contact with the bottom of the bucket?

Homework Equations


N + mg = mv^2/r

The Attempt at a Solution


I thought this was going to be a simple answer. So I set N = 0, because that is the when the rock is about to lose contact. So then I solved for v = sqrt(r*g), which is sqrt(9.8*2.8) which gave me 5.2 m/s, but it is saying it is wrong? I think my problem must be than N must be something other than 0? But I'm not sure what to put N as in that case. Can someone help me?
 
Physics news on Phys.org
  • #2
N is 0 for sure, but you used the diameter instead of the radius!
 
  • #3
Well, damn. Thanks mate haha.
 

FAQ: Circular Motion of a moving rock Problem

1. What is circular motion?

Circular motion is the movement of an object along a circular path at a constant speed. This means the object is constantly changing direction but maintains the same speed.

2. How do you calculate the velocity of an object in circular motion?

The velocity of an object in circular motion can be calculated by dividing the circumference of the circle by the time it takes to complete one full revolution. This is also known as the object's tangential velocity.

3. What is centripetal force?

Centripetal force is the force that keeps an object moving in a circular path. It is directed towards the center of the circle and is always perpendicular to the object's velocity.

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

Centripetal force is the inward force that keeps an object moving in a circular path, while centrifugal force is the outward force that appears to push an object away from the center of the circle. In reality, centrifugal force is an inertial force and does not actually exist.

5. How does the mass of an object affect its circular motion?

The mass of an object does not affect its circular motion, as long as the centripetal force remains constant. However, a larger mass may require a greater centripetal force to maintain the same circular path at a given speed.

Similar threads

Vertical circular motion
Replies
8
Views
639
Circular Motion: Swinging a rock on a string in a vertical circle....
Replies
1
Views
2K
Reaction force be 0 at top of circular path swing?
Replies
3
Views
2K
Tension of string acting on stone moving in horizontal circular motion
Replies
19
Views
2K
A Car on a Banked Curve Moving in Uniform Circular Motion
Replies
7
Views
2K
Circular motion grade 12 physics
Replies
4
Views
1K
Proper use of inequality symbols in equations to do with circular motion
Replies
2
Views
825
Force Exerted Non-Uniform Circular Motion
Replies
4
Views
2K
Circular Motion and centripetal acceleration
Replies
6
Views
2K
Circular motion of a mass on a string on an inclined plane
Replies
14
Views
3K

Hot Threads

Recent Insights

Back
Top