Two blocks are placed at the ends of a horizontal massless board, as in the drawing. The board is kept from rotating and rests on a support that serves as an axis of rotation. The block on the right has a mass of 4.4 kg. Determine the magnitude of the angular acceleration when the system is allowed to rotate.

The angular acceleration is  

Explanation:

The  diagram for this question is shown on the first uploaded image (gotten from study website)

From the question we are told that

      The mass of the block on the right is  

       The mass of the block on the left is

       The distance of the left mass to the center is  

       The distance of the right  mass to the center is  

At the point the system is allowed to rotate the upward torque is mathematically evaluated as

substituting values

The moment of inertia of the system is  mathematically represented as

substituting values

The angular acceleration is mathematically represented as

substituting values

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.