Answer:
B)a tool to drop temperatures, mercury, an electric current, and a tool to measure resistance
Answer:
a) 
b)
c)
d)= 0 and the direction of motion is equal to zero
Explanation:
a) compton shift



b) the new wavelength



![=hc[\frac{1}{\lambda'}-\frac{1}{\lambda}]](https://tex.z-dn.net/?f=%3Dhc%5B%5Cfrac%7B1%7D%7B%5Clambda%27%7D-%5Cfrac%7B1%7D%7B%5Clambda%7D%5D)
![\Delta E = 6.626*10^{-34}*(3*10^8)[\frac{1}{14.84*10^{-12}}-\frac{1}{4.8*10^{-12}}]](https://tex.z-dn.net/?f=%5CDelta%20E%20%3D%206.626%2A10%5E%7B-34%7D%2A%283%2A10%5E8%29%5B%5Cfrac%7B1%7D%7B14.84%2A10%5E%7B-12%7D%7D-%5Cfrac%7B1%7D%7B4.8%2A10%5E%7B-12%7D%7D%5D)

C)By conservation of energy, the kinetic energy of recoiling electron is equal to the magnitude of energy between the photon energy

d) the angle between the positive direction of motion

= 0
the direction of motion is equal to zero.
If you stand up in a big room and echo, your voice will echo
from the walls. As long as the room is empty. Since
the speed of sound is constant, depending on air density, the more humid the
air the faster and farther sound travels. The
speed of sound is constant, you could measure the time it takes for your voice
to echo off the walls. The same thing happens with Doppler radar, but it’s not voice,
it has higher frequency signals.<span> </span>