The triceps muscle in the back of the upper arm is primarily used to extend the forearm. suppose this muscle in a professional boxer exerts a force of 1.75 × 103 n with an effective perpendicular lever arm of 3.05 cm, producing an angular acceleration of the forearm of 115 rad/s2. what is the moment of inertia of the forearm, in kilogram meters squared?

To solve this problem it is necessary to apply the concepts related to Torque as a function of the Force and the distance radius where it is applied.

By definition the Torque can be expressed as

Where

F = Force exerted

r = Radius

Substituting we have to

Through the second definition of the rotational Torque we can then find the moment of inertia for which we have to

Where

I = Moment of inertia

Angular acceleration

Replacing

Therefore the moment of inertia is

You may have notice when you accidentally rubbed your arm with another, a 'spark' happens. This is a consequence of static electricity. When two objects are rubbed together, the electrons get excited and collide which each other producing the 'spark'. This process is called friction.