Centripetal force and total force?

In summary, the conversation discusses a problem involving a child on a swing and determining the centripetal force exerted by the ropes on the child. The formula F = mv^2/r is used to calculate the centripetal force, but the concept of "total force" is unclear. After drawing a free body diagram and considering the forces acting on the swing at its lowest point, it is determined that the "total force" refers to the tension in the ropes. The equation Fc = Ft - Fg is then used to solve for the tension.
  • #1
paperweight11
5
0

Homework Statement


A 25 kg child is on a swing, which has a radius of 2.00 m. If the child is moving 4.0 m/s at the bottom of one swing, what is the centripetal force exerted by the ropes of the swing on the child? What is the total force exerted by the ropes when the swing is at its lowest point?

Homework Equations


a = v^2/r

F = mv^2/r

The Attempt at a Solution



I have no problem with the first part of the question. You just use F = mv^2/r to figure out the centripetal force. However, I am not sure how to get the "total force." I know which way the tension is directed and everything. I'm just not really sure what total force is referring to. Any help would be greatly appreciated.

Thanks.
 
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  • #2
Draw the free body diagram. What is causing the centripetal force?

Everything is easier because the problem asks you about the lowest point, so forces either point up or down.
 
  • #3
The word "total" isn't necessary in that question. You can just as well think of it as "What is the force exerted by the ropes when the swing is at its lowest point?"
 
  • #4
edit: nvm
 
  • #5
So what it is asking for is basically the tension in the rope? If so, that is easy.

Fc = Ft - Fg

Solve for Ft.

The word "total" was throwing me off. I was convinced it meant Net force or something.
 

1. What is centripetal force?

Centripetal force is the force that acts on an object moving in a circular path, directed towards the center of the circle. It is responsible for keeping the object moving in a circular motion instead of flying off in a straight line.

2. How is centripetal force related to total force?

Centripetal force is a component of the total force acting on an object moving in a circular path. The total force is the sum of all the forces acting on the object, including the centripetal force and any other forces such as friction or air resistance.

3. What is the formula for centripetal force?

The formula for centripetal force is F = m*v^2/r, where F is the force, m is the mass of the object, v is the velocity and r is the radius of the circular path.

4. Can centripetal force act on an object moving in a straight line?

No, centripetal force can only act on an object that is moving in a circular path. If an object is moving in a straight line, there is no change in direction and therefore no need for a centripetal force.

5. How does centripetal force affect the speed of an object?

Centripetal force does not directly affect the speed of an object. It only affects the direction of the object's motion, keeping it moving in a circular path. However, the speed of the object can indirectly affect the centripetal force, as a greater speed would require a larger centripetal force to maintain the circular motion.

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