As a certain sound wave travels through the air, it produces pressure variations (above and below atmospheric pressure) given by ?P = 1.26 sin(px - 332pt) in SI units. (Note: Use the following values as needed, unless otherwise specified. The equilibrium density of air is ? = 1.20 kg/m3. Pressure variations ?P are measured relative to atmospheric pressure, 1.013 105 Pa.)
(a) Find the amplitude of the pressure variations.
Pa

(b) Find the frequency of the sound wave.
Hz

(c) Find the wavelength in air of the sound wave.
m

(d) Find the speed of the sound wave.
m/s

b.a device that inputs heat into a cool object

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.

365.25 earth days are in the year of a light year