Answer:
The the analysis for the free fall part should be done under the constant acceleration.
Explanation:
In the given problem, the jumper is falling under the free fall. Since, no external force is acting on the body therefore, the fall will be under the action gravity only. also, the acceleration due to gravity is always constant.
Therefore, the the analysis for the free fall part should be done under the constant acceleration.
Answer:
The velocity of the freight car decreases.
Explanation:
This question is answered by the conservation of momentum principle.
When the freight car is moving at a certain speed, it has a constant momentum.
We will call this M1.
The equation for M1 will be:
M1 = Mass * Speed
Now when the coal is dumped into the freight car, the Mass increases.
Since conservation of momentum states that the momentum will remain the same. We have:
M1 = (Mass of freight + Mass of coal) * Speed
Since M1 is constant, if the mass increases, the speed had to decrease to keep the equation true.
Answer:
v = 87.57 m/s
Explanation:
Given,
The initial velocity of the car, u = 0
The final velocity of the car, v = 60 mi/hr
The time period of car, t = 8 s
= 0.00222 hr
The acceleration of the car is given by the formula,
a = (v -u) / t
= 60 / 0.00222
= 27027 mi/hr²
If the car has initial velocity, u = 50 mi/hr
The time period of the car, t = 5.0 s
= 0.00139 hr
Using first equations of motion
<em> v = u + at</em>
= 50 + (0.00139 x 27027)
= 87.57 mi/hr
Hence, the final velocity of the car, v = 87.57 mi/hr
Answer:
<em>A) Beam B carries twice as many photons per second as beam A.</em>
Explanation:
If we have two waves with the same wavelength, then their intensity is proportional to their power, or the energy per unit time.
We also know that the amount of photon present in an electromagnetic beam is proportional to the energy of the beam, hence the amount of beam per second is proportional to the power.
With these two facts, we can say that the intensity is a measure of the amount of photon per second in an electromagnetic beam. So we can say that <em>beam B carries twice as more power than beam A, or Beam B carries twice as many photons per second as beam A.</em>
Answer:
Diffraction: Wave Theory
Interference: Wave Theory
Reflection: both particles and wave theories
Refraction: both particles and wave theories
