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:
a) t = 1.75 s
b) x = 31.5 m
Explanation:
a) The time at which Tom should drop the net can be found using the following equation:
Where:
: is the final height = 0
y₀: is the initial height = 15 m
g: is the gravity = 9.81 m/s²
: is the initial vertical velocity of the net = 0 (it is dropped from rest)
Hence, Tom should drop the net at 1.75 s before Jerry is under the bridge.
b) We can find the distance at which is Jerry when Tom drops the net as follows:
Then, Jerry is at 31.5 meters from the bridge when Jerry drops the net.
I hope it helps you!