Answer: c. the molecules with the highest energy evaporate first, lowering the temperature of the sample
Explanation:
The process by which liquid starts to change into vapor phase at any temperature is known as evaporation.
During evaporation , the molecules which possess higher energies escape from the upper layer into vapor phase. the molecules which escape draw energy from surroundings and thus decrease the energy of the surroundings and hence lead to decrease in temperature.
As temperature of the system is directly proportional to the energy of the system , thus decrease in energy leads to decrease in temperature.

K.E. = Kinetic energy
T = temperature
R= gas constant
Explanation:
It is given that,
Magnitude of charge, 
It moves in northeast direction with a speed of 5 m/s, 25 degrees East of a magnetic field.
Magnetic field, 
Velocity, 
![v=[(4.53)i+(2.11)j]\ m/s](https://tex.z-dn.net/?f=v%3D%5B%284.53%29i%2B%282.11%29j%5D%5C%20m%2Fs)
We need to find the magnitude of force on the charge. Magnetic force is given by :

![F=15\times 10^{-6}[(4.53i+2.11j)\times 0.08\ j]](https://tex.z-dn.net/?f=F%3D15%5Ctimes%2010%5E%7B-6%7D%5B%284.53i%2B2.11j%29%5Ctimes%200.08%5C%20j%5D)
<em>Since</em>, 
![F=15\times 10^{-6}[(4.53i)\times (0.08)\ j]](https://tex.z-dn.net/?f=F%3D15%5Ctimes%2010%5E%7B-6%7D%5B%284.53i%29%5Ctimes%20%280.08%29%5C%20j%5D)


So, the force acting on the charge is
and is moving in positive z axis. Hence, this is the required solution.
Answer:
1.5m
Explanation:
Speed of waves is given as the product of the wavelength and frequency. Sometimes when frequency is not given but the period is given, we get the frequency as the reciprocal of the period. The speed of waves is given in m/s, wavelength in m while frequency in Hz.
Speed, s= fw and making w the subject of formula,

Substituting 300, 000, 000 m/s for s and 200, 000, 000 for f then we obtain that

Becasue when you rubbed your hair while you were putting on your sweater it caused it to rub against together causing electricity thingy lol. and thats why your hair goes straigh tup.
Answer:
b
Explanation:
friction needs two objects
the two objects need to touch each other
the two objects need to either have relative movement or, tend to have relative movement urge. (kinetic friction or static friction)