Answer:
I think it's Experimental
Explanation:
it has atoms on it.
Answer:
v = 6.79 m/s
Explanation:
It is given that,
Mass of a train car, m₁ = 11000 kg
Speed of train car, u₁ = 21 m/s
Mass of other train car, m₂ = 23000 kg
Initially, the other train car is at rest, u₂ = 0
It is a case based on inelastic collision as both car couples each other after the collision. The law of conservation of momentum satisied here. So,

V is the common velocity after the collisions

So, the two car train will move with a common velocity of 6.79 m/s.
Answer:
The elevator must be moving upward.
Explanation:
During the motion of an elevator, the weight of the person deviates from his or her actual weight. This temporary weight during the motion is referred to as "Apparent Weight". So, when the elevator is moving downward, the apparent weight of the person becomes less than his or her actual weight.
On the other hand, for the upward motion of the elevator, the apparent weight of the person becomes more than the actual weight of that person.
Since the apparent weight (645 N) of the student, in this case, is greater than the actual weight (615 N) of the student.
<u>Therefore, the elevator must be moving upward.</u>
Answer:
2.80321285141
Explanation:
= Thickness of glass = 4.5 mm
= Thermal conductivity of glass = 0.8 W/mK
= Combined thermal resistance = 
= Thickness of air = 6.6 mm
= Thermal conductivity of air = 0.024 W/mK
The required ratio is the inverse of total thermal resistance

The ratio is 2.80321285141
1. Stop transmitting start and stop sending photons. This is typical morse code like transmissions of information. By varying the pattern of starts stops you vary the information sent. Also used in digital communications over radios, modems, and pulse dialing over radio/phones.
<span>2. Change the frequency. You use a pattern of shorter and longer wavelengths of radio waves higher and lower energies of individual photons to transmit information. This is frequency modulation </span>