Understanding Torque and Inertia: How Does it Affect Motion?

Torque is the rotational equivalent of force, and inertia is the rotational equivalent of mass. In other words, torque is the force that causes rotational motion, while inertia is the resistance to change in rotational motion. So, to overcome inertia and get a wheel spinning, you need enough torque to overcome the resistance caused by the moment of inertia. However, friction also plays a role in maintaining the rotation of the wheel. If the driving torque is not strong enough to overcome both the inertia and friction, the wheel will not spin. Therefore, torque and inertia are closely related and both need to be considered in order to get a wheel spinning successfully.
  • #1
schip666!
595
0
After all this recent talk of torque and power I figure I can post my stupid question of the week:

How does torque relate to inertia?

Say I have a nice balanced wheel that I want to spin. I can calculate the moment of inertia but I'm too old to remember how to figure out how much torque and/or power I need to over come the inertia (and friction) to get it going. I got stalled here in dimensional analysis:

moment of inertia == kg·m²
energy (joules) == kg·m²/s² (Newton-meters)
torque == joules/radian == kg·m²/s² (same as energy but through X degrees of rotation)
From wiki: A torque of 1 N·m applied through a full revolution will require an energy of exactly 2(pi) joules.

So, now ignoring friction, can I figure that the driving torque just influences the acceleration? And then it's only friction that keeps my wheel from spinning when the motor is too small?
 
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  • #2
schip666! said:
How does torque relate to inertia?
The same way as force relates to mass.
 

1. What is torque and how does it affect motion?

Torque is a measure of the force that causes an object to rotate around an axis. It is affected by the magnitude and direction of the applied force, as well as the distance between the force and the axis of rotation. In terms of motion, torque can change the rotational speed or direction of an object.

2. How is torque related to inertia?

Inertia is the tendency of an object to resist changes in its state of motion. Torque is directly related to inertia, as a larger torque is required to overcome the inertia of an object and produce a rotational motion.

3. What factors affect the amount of torque produced?

The amount of torque produced is affected by the magnitude of the applied force, the distance between the force and the axis of rotation, and the angle at which the force is applied.

4. How does torque affect the stability of an object?

Torque can affect the stability of an object by causing it to rotate or topple over. The greater the torque, the more likely an object is to lose its stability.

5. What are some real-life examples of torque and inertia in action?

Some examples include a car accelerating around a curve (torque is produced by the friction between the tires and the road), a diver rotating in the air (torque is produced by the diver's movements), and a spinning top (inertia keeps the top spinning until an external force, such as friction, slows it down).

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