The blade of an electric shaver vibrates in a simple harmonic motion with a frequency 235.0 hz over a distance 6.6 mm. what is the amplitude of vibration?

3.3 mm

Explanation:

The electric shaver is vibrating back and forward covering a distance of 2 mm, therefore, the amplitude of this vibration is always the half of the distance.

So the expression to use is:

A = D/2

A = 6.6 / 2 = 3.3 mm

Now, suppose you want the speed of this vibration:

V = 2πfA

V = 2π * 235 * 0.0033

V = 4.87 m/s

magnified images possible images can be real = projected onto a screen

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.