Calculating Acceleration of a Ball Rolling Down a Slope

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Homework Help Overview

The discussion revolves around calculating the acceleration of a ball rolling down an 8.5 meter slope inclined at an angle of 2.2 degrees. The original poster presents the problem and their initial attempts at finding the dimensions of the ramp and the triangle formed by it.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the need to identify the source of acceleration and how it applies along the ramp. There are suggestions to consider the ball's rolling behavior and the forces acting on it, including moments of inertia and torque. Some participants question the necessity of the ramp's length in determining acceleration.

Discussion Status

The discussion is ongoing, with various approaches being explored. Some participants have offered guidance on drawing free body diagrams and resolving gravitational components, while others emphasize the importance of assumptions regarding the ball's motion and properties. There is an indication that further clarification from the original poster may be needed.

Contextual Notes

There is a suggestion that the original poster may not have provided all relevant information, and assumptions about the ball's behavior, such as rolling without slipping, are under consideration.

Biasface
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Homework Statement


A ball is placed at the top of an 8.5 meter slope, which is at an angle of 2.2 degrees. What is the ball's acceleration?

θ of ramp=2.2
length of ramp=8.5
initial velocity (x and y)=0

Homework Equations


a = (v - v0)/t

The Attempt at a Solution


I tried for 45 minutes to solve this problem. All i could manage to do was find the dimensions of the ramp/triangle, which has side lengths 8.5, 0.32, and 8.49. The angle measures are 90, 2.2 and 87.8.
 
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You need to address the source of its acceleration and calculate the percent of that will be applied along the ramp.

I suspect there is more to this problem than just getting the acceleration because only the angle is required for that. The length of the ramp is not required to determine the acceleration of the ball.
 
You need to make some assumptions to solve this problem. I would assume the ball rolls without slipping, and that it is a solid ball of uniform density.
Draw a free body diagram of the ball. What forces act on it, in what directions?
What do you know about moments of inertia? Any equations you can quote for that?
 
Biasface said:

Homework Equations


a = (v - v0)/t

That equation won't help you. All you know is that ##v_o=0##.

Have you tried resolving ##\vec{g}## into two components?
 
The easiest way to do this is to calculate the torque about the point of contact of the sphere with the plane.
Then you can use the moment of inertia about the same point of contact using the parallel axis theorem.
If you use torque about the center of mass of the sphere then you need to consider the frictional
force which provides the torque. You then have to write an additional equation regarding the
linear acceleration and eliminate the force of friction.
 
The OP needs to come back with some show of effort before any further help is offered. I suspect that there's more to the actual problem statement that hasn't been shared.
 

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