Calculating Angular Speed: Simple or Complicated?

In summary, the formula for finding the instantaneous angular speed of a wheel that accelerates from rest is final angular speed = initial angular speed + angular acceleration(change in time). However, this formula may seem too simple due to the fact that the given acceleration is in units of linear acceleration, not angular acceleration. To solve this, one can use the formula \alpha r = a, and reason that the linear velocity of the center of the wheel after the given time can be used to calculate the speed of rotation of the wheel, since it is in contact with the Earth.
  • #1
angel_romano
5
0
If a wheel accelerates from rest at 1.0 m/s^2 and I need to find the instantaneous angular speed of the wheel at .10s would this be the proper formula:

final angular speed=initial angular speed + angular acceleration(change in time)

When I use this formula, it comes out to .10 rad/s which just seems to simple.
 
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  • #2
Well, you state the wheel accelerates from rest at 1.0m/s^2. m/s^2 is a measurement of linear acceleration not angular acceleration.
 
  • #3
But how does the angular acceleration fit in then?

I have linear formulas, but I'm not sure which one I would use.
 
  • #4
[tex] \alpha r = a [/tex]
 
  • #5
With a little bit of reasoning one could solve it with basic knowledge...
Via the linear acceleration one could calculate the linear velocity of the centre of the wheel after the given time. At this stage one could reason that the Earth is moving with the same speed in the opposite direction while the wheel is standing still, hence the speed of rotation of the wheel since it is in contact with the earth.
 

1. What is angular speed and how is it different from linear speed?

Angular speed is a measure of how quickly an object is rotating or moving in a circular path. It is different from linear speed because it takes into account the distance traveled along a circular path, rather than a straight line.

2. How is angular speed calculated?

Angular speed is calculated by dividing the angle traveled in radians by the time it takes to travel that angle. This can be represented by the formula ω = θ/t, where ω is the angular speed, θ is the angle in radians, and t is the time.

3. Is calculating angular speed a simple or complicated process?

It depends on the situation. For a simple circular motion with constant speed, calculating angular speed is relatively straightforward. However, for more complex motions, such as non-uniform circular motion, the calculation can be more complicated and may require additional equations.

4. How does angular speed relate to rotational speed?

Angular speed and rotational speed are essentially the same thing. Rotational speed is simply the angular speed expressed in revolutions per unit time, while angular speed is typically expressed in radians per unit time.

5. Are there any real-life applications of calculating angular speed?

Yes, there are many real-life applications of calculating angular speed. Some examples include determining the speed of rotating machinery in factories, measuring the rotation of wheels in vehicles, and calculating the speed of celestial bodies in astronomy.

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