Circular Motion Equation homework

In summary, the participants in the conversation discussed a problem involving circular motion and the use of equations such as F=ma and τ=Id2θ/dt2. One person shared their solution and got a result of 6 m/s2, but it did not match any of the answer choices. Another person agreed with the solution but pointed out that the force of tension from the string should also be considered. They also suggested using different equations such as I=mR2. However, the original solution was still considered valid.
  • #1
Sarah00
64
1

Homework Statement


2015_06_27_6_20_40.gif


Homework Equations


Circular Motion Equation

The Attempt at a Solution


I solved the problem and got the result to be 6 m/s2 but it is not one of the answers. I was pretty sure of my solution. So, are all choices wrong?

F = ma
mg sin 37 = ma
a = g sin 37 = 6.01 m/s2
 
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  • #2
Yep I agree with you.
 
  • #3
I got 5.9 ms-2 so same answer if g = 9.8 ms-2 instead of 10.
BUT - I don't like your rationale.
The force on the mass includes the tension from the string which you have ignored.
I suggest instead τ = Id2θ/dt2
I = mR2
etc.
Answer is the same though.
EDIT: on the other hand, maybe you were quick enough to realize that the tension vector, being orthogonal to the tangent vector, cannot impart force, therefore acceleration, in the tangential direction, making what you originally did 100% justified.
 
Last edited:

1. What is circular motion?

Circular motion is the movement of an object along a circular path. It is characterized by a constant radius and a constant speed, but a changing velocity due to the change in direction.

2. What is the equation for circular motion?

The equation for circular motion is v = rω, where v is the linear velocity, r is the radius, and ω is the angular velocity.

3. How do I calculate the velocity of an object in circular motion?

To calculate the velocity of an object in circular motion, you can use the equation v = rω. First, determine the radius of the circular path and the angular velocity of the object. Then, plug these values into the equation to find the linear velocity of the object.

4. What is an example of circular motion?

An example of circular motion is the motion of a planet around the sun. The planet moves along a circular path around the sun, with a constant radius and a constant speed, but a changing velocity due to the change in direction.

5. How do I solve circular motion equations?

To solve circular motion equations, you need to have a good understanding of the basic concepts and equations involved. Start by identifying the variables given in the problem and the ones you need to solve for. Then, use the appropriate equation and plug in the known values to find the unknown value. It is important to pay attention to units and make sure they are consistent throughout the calculation.

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