Staals half
1 gram left
0.3 grams left
half lives are normally written in years
it goes likt this
A=final amount
P=initila amount
t=time elapsed
h=time half life is (same units as time)
let's use days as the units of time
we are given
initial amount=1gram
final amount=0.3gram
time=4 days
so
solve for h
take the ln of both sides
times both sides by h
divide both sides by ln(0.3)
use calculator
h=2.30287
3 sig figs
h=2.303 days
10
A) 24 ribbons
B)1/28yards
11.u have 1/2 how?
Step-by-step explanation:
We want to find two things-- the speed of the boat in still water and the speed of the current. Each of these things will be represented by a different variable:
B = speed of the boat in still water
C = speed of the current
Since we have two variables, we will need to find a system of two equations to solve.
How do we find the two equations we need?
Rate problems are based on the relationship Distance = (Rate)(Time).
Fill in the chart with your data (chart attached)
The resulting speed of the boat (traveling upstream) is B-C miles per hour. On the other hand, if the boat is traveling downstream, the current will be pushing the boat faster, and the boat's speed will increase by C miles per hour. The resulting speed of the boat (traveling downstream) is B+C miles per hour. Put this info in the second column in the chart. Now plug it into a formula! <u>Distance=(Rate)(Time) </u>Now solve using the systems of equations!
Answer:
(3,16)
Step-by-step explanation:
The degrees of freedom of the critical value F are (k-1,n-k).
We are given that there are four sample group, so,
k=4.
Also, we are given that the each four groups contains five observations, so,
n=4*5
n=20
The critical value F has degree of freedom
(k-1,n-k)
(4-1,20-4)
(3,16).
Thus, the degrees of freedom for the critical value of F are (3,16).
