Remark
You have to pick a velocity for an ultra sound wave. I'm going to take the sound velocity to be 331 m/s in air, because I'm assuming that is what is meant: it is the sound a bat would make once he emits the ultrasound to a microphone like device that receives it. The media through which that happens is air.
Givens
v = 331m/s
f = 4 *10^4 hz
Formula
velocity = wavelength * frequency
v =
*f
331/(4*10^4) = 
0.008275 = 
8.275*10^-3 = 
Oil spill on land and in the oceans and kills wildlife like the great barear reef
Answer: 4 ft/s
Explanation:
Given
height of man
speed of person 
height if street light
Let x be the distance between person and street light and y be the length of his shadow
From diagram
as the two triangle ADE and ABC are similar therefore we can say that




differentiate above Equation w.r.t time we get


Explanation:
electrical potential = (6.6-3.4)/0.20
= 16 uc/m
IBR is the thermal decomposition of iodine(I) bromide to produce iodine and
bromine. This reaction takes place at a temperature of over 40,5°C and is written as:
<span>2IBr ⇄ I2 + Br2
</span>
Equilibrium is a state of dynamic balance where the ratio of the product and reactant concentrations is constant.<span> You can calculate the equilibrium concentration if you know the equilibrium constant Kc (Kc=I^2*Br^2/IBR^2) and the initial concentration for the reaction. The initial concentration is obtained from ICE Table.</span>