Motion in a Circle: True/False/Less/Greater/Equal

In summary, the conversation discusses a small mass M moving in circles on a frictionless table with varying forces and radii. The kinetic energy at circle y is four times that at circle x, the angular momentum at circle x is equal to that at circle y, the angular velocity at circle x is one quarter that at circle y, and the work done by the force is greater than 0 as M moves from circle x to circle y. Additionally, there is no torque on M while it moves from circle x to circle y.
  • #1
gummybeargirl
22
0

Homework Statement


A small mass M attached to a string slides in a circle (x) on a frictionless horizontal table, with the force F providing the necessary tension (see figure). The force is then increased slowly and then maintained constant when M travels around in circle (y). The radius of circle (x) is twice the radius of circle (y).
1) M's kinetic energy at y is four times that at x.
2) M's angular momentum at x is ... that at y.
3) M's angular velocity at x is one quarter that at y.
4) As M moves from x to y, the work done by F is ... 0.
5) While going from x to y, there is no torque on M
Each has the options of True/False/Less than/Greater than/Equal to

2. The attempt at a solution
1) False
2) Greater than
3) False
4) False
5) True
 

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  • #2
Hey, I just saw your other post too. So, same as that one, could you first explain your reasoning for each answer? It helps a lot in seeing if you got the problem right.
 
  • #3
Nevermind! I was able to get this one as well. My answer turned out to be
1) true
2) equal to
3) true
4) greater than
5) true
 

1. Is motion in a circle always true?

No, motion in a circle can be false if the object is moving in a straight line or in a different shape, such as an ellipse.

2. Is the speed always less in motion in a circle compared to a straight line?

Yes, the speed in a circle is always less than the speed in a straight line due to the change in direction constantly occurring in a circle.

3. Can the acceleration be greater in motion in a circle than in a straight line?

Yes, the acceleration in a circle can be greater than in a straight line if the object is moving at a higher speed or if the radius of the circle is smaller.

4. Is the distance traveled always equal in a circle compared to a straight line?

No, the distance traveled in a circle is not always equal to the distance traveled in a straight line. The distance in a circle depends on the radius and the number of revolutions, while the distance in a straight line is simply the length of the path.

5. Do the forces acting on an object in motion in a circle have to be equal?

No, the forces acting on an object in motion in a circle do not have to be equal. In fact, there must be a net force acting towards the center of the circle in order to maintain the circular motion. This force is called the centripetal force.

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