The amplitude, or magnitude, of a sinusoidal source is the maximum value of the source. What is the amplitude of the voltage source described as v(t)=50cos(2000t−45∘) mVv(t)=50cos⁡(2000t−45∘) mV ?

A = 0.05 V

Explanation:

Sinusoidal Functions

A sinusoid or sinusoidal function is a sine or cosine which general equation is

Or also

Where A is the amplitude or maximum value, w is the angular frequency, t is the time and is the phase shift.

Comparing the given expression with the general formula

We can establish that A=50 mV = 0.05 V

d) physical means can be used to separate the components of air.

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.