Answer:
5.5 min
Step-by-step explanation:
At time t=0 you have 72 grams
at time t = 22 min you have 4.5 grams.
Now
4.5/72 = (1/2)^(t/half-life)
and t=22, so
4.5/72 = (1/2)^(22/half-life)
taking log of both sides:
log(4.5/72)=(22/half-life)log(1/2)
solving for half-life gives half-life = 11/2 = 5.5min
Answer: B
Step-by-step explanation:
Look at graph
Answer:
0.143 to the nearest thousandth.
Step-by-step explanation:
7x = 1
To find the value of x be divide both sides of the equation by 7:
7x/7 = 1/7
x = 1/7
Converting to decimal:
1/7 = 0.1428571429.
Answer:
C = 4pi or approximately 12.56
Step-by-step explanation:
The circumference of a circle is given by
C = 2*pi*r
C = 2*2*pi
C = 4pi
If we approximate pi by 3.14
C = 12.56
