A muon is a type of subatomic particle. If a muon is at rest in the laboratory, it will decay into an electron after about 2 microseconds. Suppose an observer watches a muon travel through the atmosphere at 90% of the speed of light. How does the lifetime of the moving muon compare to the laboratory muon for an observer at rest with respect to the lab

  = 2.29

Explanation:

For this exercise as the muon goes at speeds close to the speed of light we must use relativists

          t =

The proper time is the decay time in the reference frame where the muon is fixed ( laboratory), t_p = 2 10⁻⁶ s and the relation

            v / c = 0.90

let's calculate

          t = 2 10-6 / Ra (1 - 0.9²)

          t = 4.59 10⁻⁶ s

the ralation is

          = 2.29

seeing the graph would

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.