Solve Flywheel & Torque Homework: Find Torque

In summary, flywheels are large, massive wheels used to store energy and release it quickly for high power tasks. An industrial flywheel with a 1.5 m diameter and a mass of 270 kg has a maximum angular velocity of 1500 rpm. To find the torque exerted on the machine, the formula T = I alpha is used with the inertia (I) calculated using the formula I = 1/2mr^2. Using this method, the torque exerted by the flywheel was found to be 51.09 N*m. However, since the problem does not mention any rate of angular acceleration or deceleration, it is not possible to accurately calculate the energy of the flywheel in a constant
  • #1
SherBear
81
0

Homework Statement


Flywheels are large, massive wheels used to store energy. They can be spun up slowly, then the wheel's energy can be released quickly to accomplish a task that demands high power. An industrial flywheel has a 1.5 m diameter and a mass of 270 kg. Its maximum angular velocity is 1500 rpm. How much torque does the flywheel exert on the machine?


Homework Equations


to find Wf I used (1/2 K ) = 1/2 I wf ^ 2

then Wf=Wo+alpha(t)

then T for torque=I alpha

The Attempt at a Solution



to find Wf I used (1/2 K ) = 1/2 I wf ^ 2

=(1/2 (9.4*10^5 (this is what the amount of energy stored) = 1/2 (70.3125) <--This number is I=1/2mr^2 (wf^2)

I rearranged this to find Wf
Wf^2= .5(9.4*10^5) / .5 (70.3125)

wf= sqrt 470,000 / 35.15
= sqrt 13371.26
wf = 115.63

then i used wf=wo+alphat to find the angular acceleration
alpha=wf / wo + t
alpha=115.63 / 157 rad/s+2.1 s
alpha = .7267

then torque=I alpha
=70.3125 (.7267)
T=51.09 N*M

It was wrong and I have no idea what I'm doing wrong
 
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  • #2
The flywheel is turning at a constant speed. How much energy does the flywheel have in this condition?
 
  • #3
The problem needs to indicate some rate of angular acceleration or deceleration such as change in angular velocity over some period of time, otherwise, if there's no change in angular velocity, then as SteamKing mentioned, there's no torque.
 

Related to Solve Flywheel & Torque Homework: Find Torque

1. What is a flywheel and how does it work?

A flywheel is a mechanical device that stores rotational energy and helps to maintain a constant speed or torque in a machine. It works by storing kinetic energy in its rotating mass and releasing it as needed to keep the machine running smoothly.

2. How do you calculate torque?

To calculate torque, you will need to know the force applied to an object (in Newtons) and the distance between the force and the pivot point (in meters). Multiply the force by the distance to get the torque, which is measured in Newton-meters (Nm).

3. How can I determine the torque required for a specific task?

The torque required for a task depends on the force needed to overcome the resistance or load. To determine this, you will need to know the distance between the force and the pivot point, as well as the magnitude of the force. Use the formula for torque (T = F * d) to calculate the required torque.

4. What is the relationship between torque and rotational speed?

Torque and rotational speed have an inverse relationship, meaning that as torque increases, rotational speed decreases. This is because torque is a measure of the force that causes an object to rotate, and as the force increases, the object will rotate at a slower speed.

5. Can you give an example of how to apply torque and flywheels in real-life situations?

One example of how torque and flywheels are used is in automobiles. The flywheel helps to keep the engine running smoothly by storing excess energy and releasing it when needed. This helps to maintain a constant speed and prevents the engine from stalling. Additionally, torque is used to tighten bolts and screws, as well as in machines like drills and lathes to create rotational motion.

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