Angular Acceleration of toy train

Click For Summary
The discussion focuses on calculating the angular acceleration of a toy train on a horizontal track with a diameter of 1.4 meters and a rolling friction coefficient of 0.12. The participants clarify that to find the angular acceleration, one can use the relationship between linear acceleration and angular acceleration, even without a specific mass value, as it cancels out in the equations. The calculated angular acceleration is determined to be 1.68 rad/s². Additionally, the time taken for the train to stop from an initial angular speed of 16 rpm is also a point of interest, although not fully explored in the discussion. Overall, the thread emphasizes problem-solving in physics related to angular motion.
carleon
Messages
6
Reaction score
0
Hi, thanks for taking a look!

A toy train rolls around a horizontal 1.4-m-diameter track. The coefficient of rolling friction is 0.12.
(a) What is the magnitude of the train's angular acceleration after it is released?
(b) How long does it take the train to stop if it's released with an angular speed of 16 rpm?

I think I know which equations to use: α = ω^2*r and a = rα, but there is no mention of velocity in the problem so I am stuck.
 
Physics news on Phys.org
welcome to pf!

hi carleon! welcome to pf! :smile:
carleon said:
(a) What is the magnitude of the train's angular acceleration after it is released?

find a (from F = ma), then divide by r to get α :wink:
 


Thanks, but since mass isn't given, how would I find F=ma?
 
call the mass "m" … it'll cancel :smile:
 
I got it! α=1.68rad/s^2

Thanks a bunch. :biggrin:
 

Thread 'Magnitude of buoyant force in fluids of different densities'

The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?
View full post »

Similar threads

How Does Rolling Friction Affect a Toy Train's Motion on a Circular Track?
  • · Replies 10 ·
Replies
10
Views
3K
Angular velocity- A toy train rolls around a horizontal track
  • · Replies 8 ·
Replies
8
Views
916
Friction Required for Billiard Ball to Roll without Slipping
  • · Replies 60 ·
3
Replies
60
Views
4K
Conservation of Angular Momentum of Train on Disk
  • · Replies 6 ·
Replies
6
Views
3K
Calculating Angular Acceleration and Stopping Time for a Rolling Train
  • · Replies 2 ·
Replies
2
Views
10K
Acceleration around a running track
  • · Replies 3 ·
Replies
3
Views
3K
Angular velocity and acceleration of a plank
  • · Replies 7 ·
Replies
7
Views
3K
Rolling without slipping problem
  • · Replies 42 ·
2
Replies
42
Views
3K
Rotational Motion: Average angular acceleration of a CD
  • · Replies 2 ·
Replies
2
Views
6K
Nonuniform circular motion toy train
  • · Replies 1 ·
Replies
1
Views
7K