Two flywheels of negligible mass and different radii are bonded together and rotate about a common axis (see below). the smaller flywheel of radius 13 cm has a cord that has a pulling force of 50 n on it. what pulling force (in n) needs to be applied to the cord connecting the larger flywheel of radius 22 cm such that the combination does not rotate?

Explanation:

As we know that the combination is maintained at rest position

So we will take net torque on the system to be ZERO

so we know that

here we will have

so we have

so we have

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.

1 is a answer of a question