Ball rolling down an incline angular and linear acceleration

Click For Summary
A ball with a moment of inertia of bmr^2 rolls down an inclined plane at angle O, and its linear acceleration is derived from the equations of motion. The net force acting on the ball is mgcos(O) minus the frictional force, leading to the equation a = gcos(O)/(1+b). The discussion highlights the importance of correctly identifying the components of weight parallel to the incline, confirming it as mgsin(O). The final expression for linear acceleration is gsin(O)/(1+b). The calculations and reasoning are validated by participants in the thread.
Fascheue

Homework Statement



A ball with moment of intertia bmr^2 rolls without slipping down a plane inclined at angle O. What is it’s linear acceleration?

Homework Equations



Fnet= ma

T = F x r

T = IO’’

a = rO’’

The Attempt at a Solution



Fnet = mgcos(O) - FfT = FfrT = IO’’

Ffr = bmr^2O’’

Ff = bmrO’’Fnet = mgcos(O) - BmrO’’a = O’’r

a/r = O’’Fnet = mgcos(O) - bma

ma = mg cos(O) - bma
a = gcos(O) - ba

a + ba = gcos(O)

a(1+b) = gcos(O)

a = gcos(O)/(1+b)
 
Physics news on Phys.org
Fascheue said:
Fnet = mgcos(O) - Ff
Check this: What is the component of the weight parallel to the plane?
 
  • Like
Likes Fascheue
Doc Al said:
Check this: What is the component of the weight parallel to the plane?
Oops, would it be mgsin(O)?

I believe that would give an answer of gsin(O)/(1+b) following the rest of my steps.
 
Fascheue said:
Oops, would it be mgsin(O)?
Yep.

Fascheue said:
I believe that would give an answer of gsin(O)/(1+b) following the rest of my steps.
Looks good to me.
 
  • Like
Likes Fascheue
Thread 'Correct statement about size of wire to produce larger extension'
The answer is (B) but I don't really understand why. Based on formula of Young Modulus: $$x=\frac{FL}{AE}$$ The second wire made of the same material so it means they have same Young Modulus. Larger extension means larger value of ##x## so to get larger value of ##x## we can increase ##F## and ##L## and decrease ##A## I am not sure whether there is change in ##F## for first and second wire so I will just assume ##F## does not change. It leaves (B) and (C) as possible options so why is (C)...

Similar threads

  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
Replies
8
Views
5K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 42 ·
2
Replies
42
Views
3K
  • · Replies 18 ·
Replies
18
Views
5K
Replies
11
Views
3K