How Do You Calculate Angular Acceleration and Revolutions of a Stopping Wheel?

Click For Summary
The wheel initially spins at 800 rad/s and comes to a stop in 14 seconds, resulting in an angular acceleration of approximately 57.1 rad/s². To find the total number of revolutions during this time, the angular displacement can be calculated using the formula for uniform acceleration. This yields about 9.09 revolutions as the wheel decelerates. The discussion emphasizes the similarity between angular and linear motion equations for solving such problems. Understanding these concepts is crucial for accurately calculating angular acceleration and revolutions.
badula
Messages
1
Reaction score
0

Homework Statement



A wheel is spinning at 800 rad/s. A torque is applied to the wheel until it stops spinning 14 seconds later. What is the angular acceleration, and how many revolutions did it go through?

v=800 read/s
t=14 s



Homework Equations



angular acceleration = delta w / delta t
1 revolution = 360 degrees = 2 pi rad



The Attempt at a Solution



delta w/delta t = 800/14 = 57.1 rads/s2

57.1 / 2 pi = 9.09 revolutions
 
Physics news on Phys.org
Welcome to PF!

Hi badula ! Welcome to PF! :smile:

(have a pi: π and a delta: ∆ and an omega: ω :wink:)
badula said:
A wheel is spinning at 800 rad/s. A torque is applied to the wheel until it stops spinning 14 seconds later. What is the angular acceleration, and how many revolutions did it go through?

Hint: you can use the usual linear equations of motion for uniform acceleration …

it's just like a linear speed of 800 m/s, stopping after 14 s, but with rad instead of m. :wink:
 
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?

Similar threads

  • · Replies 8 ·
Replies
8
Views
923
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 1 ·
Replies
1
Views
8K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
8
Views
3K
Replies
3
Views
2K