Answer:
120 grams will be left after 180 years.
Step-by-step explanation:
A radioactive half-life refers to the amount of time it takes for half of the original isotope to decay and its given by

where,
= quantity of the substance remaining
= initial quantity of the substance
= time elapsed
= half life of the substance
From the information given we know that:
- The initial quantity is 480 g,
- The half-life is 90 years,
- 180 years is the time elapsed.
And we want to find how much will be left. For this we use the above formula.

120 grams will be left after 180 years.
Answer:
80pi-60pi
Step-by-step explanation:
To find how much Juan ran, we must find the circumference.
pi *30*2=60*pi (which is how much Juan ran.)
pi*40*2=80*pi (which is how much Miguel ran)
80pi-60pi would be how much farther Miguel ran than Juan.
Answer:
The answer should B, only one makes sense
Answer:
a. 1.25 laps per min
b. .8 min per lap
c. 17.6 minutes
Step-by-step explanation: