At the instant shown during deceleration, the velocity of an automobile is 40 ft/s to the right. knowing that the velocity of the contact point a of the wheel with the ground is 5 ft/s to the right, determine (a) the instantaneous center of rotation of the wheel, (b) the velocity of point b, (c) the velocity of point d.

wavelength divides in half and speed stays the same.

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.