Calculate Angular Acceleration of Rotational Motion: 4.9rev in 1s

Click For Summary
SUMMARY

The discussion focuses on calculating the angular acceleration of a tire that completes 4.9 revolutions in 1 second. The initial attempt incorrectly applied the formula a = w/t, leading to an erroneous result of 30.7876 rad/s². The correct approach involves using the formula for angular displacement analogous to s = (1/2)at², which accounts for the changing angular velocity during acceleration. This method provides a more accurate calculation of angular acceleration.

PREREQUISITES
  • Understanding of angular motion concepts
  • Familiarity with angular velocity and acceleration
  • Knowledge of rotational kinematics equations
  • Ability to convert between revolutions and radians
NEXT STEPS
  • Study the rotational kinematics equations, particularly the relationship between angular displacement, angular acceleration, and time.
  • Learn how to derive angular acceleration using the formula θ = ω₀t + (1/2)αt².
  • Practice converting between different units of angular measurement, such as revolutions to radians.
  • Explore examples of non-constant angular acceleration scenarios in physics.
USEFUL FOR

Students studying physics, particularly those focusing on rotational motion, as well as educators seeking to clarify concepts of angular acceleration and kinematics.

islanderman7
Messages
5
Reaction score
0

Homework Statement


A tire placed on a balancing machine in a service station starts from rest and turns through 4.9 revolutions in 1.0 s before reaching its final angular speed. Calculate its angular acceleration.

I need my answer in
rad/s^2


Homework Equations


a=w/t
1rev= 2n rad


The Attempt at a Solution


Converted rev/s to rad/s
4.9rev/s * (2n rad/s)/ 1 rev= 30.7876 rad/s

a=w/t
a= (30.7876 rad/s)/ 1sec => 30.7876 rad/s^2

This answer comes out wrong.

What am I doing wrong?
 
Physics news on Phys.org
It's not a constant angular velocity question. Angular velocity changes with time, so you can't just use a=w/t. You need a formula analogous to s=(1/2)*a*t^2 for linear motion. It looks very similar, just the meaning of the letters changes.
 
Okay thanks. I get it now.
 

Similar threads

  • · Replies 13 ·
Replies
13
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
Replies
9
Views
3K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K