Answer:
15.75 cm
Explanation:
focal length of convex lens, f = + 9 cm
position of object, u = - 21 cm
Let the distance of image is v.
Use lens equation
1 / f = 1 / v - 1 / u
1 / 9 = 1 / v + 1 / 21
1 / v = 1 / 9 - 1 / 21 = (21 - 9) / (21 x 9)
1 / v = 12 / 189
v = 15.75 cm
The two different isotopes have weights :
w1 = 78.918 amu
w2 = 80.916 amu
average weight w3 = 79.903 amu
The mixing of two components can be modeled as
let the fraction of w1 be 'x'
hence
now this is a linear equation in 'x'. Substituting the values we get
x = 0.507
hence the percentage of Br79 = 50.7% and the percentage of BR81 = 49.3%
Answer:
Increasing until terminal velocity is reached
Explanation:
Provided the scream is a constant pitch at the source, Doppler effect will make the pitch increase as the velocity of the source towards the listener increases.