Asanding disk with rotational inertia 2.0 x 10-3 kg·m2 is attached to an electric drill whose motor delivers a torque of magnitude 32 n·m about the central axis of the disk. about that axis and with torque applied for 62 ms, what is the magnitude of the(a) angular momentum and(b) angular velocity of the disk?

Explanation:

It is given that,

Moment of inertia of a standing disk,

Torque acting on the motor,

Time for which the torque is applied,

(a) The relationship between the angular momentum and the torque is given by :

Where

L is the angular momentum of the disk

(b) Let is the angular velocity of the disk. The relation between the angular velocity and the angular momentum is given by :

Hence, this is the required solution.

change tension

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.