Answer:
The linear speed is
Step-by-step explanation:
step 1
Find the circumference of the circle
The circumference is equal to
we have
substitute
step 2
Find the linear speed in feet per minute
we know that
The wheel is rotating at 10 revolutions per minute
Convert revolutions to feet
Remember that
One revolution is equal to the circumference of the circle
so
10 revolutions is equal to
therefore
The linear speed is
Note: a radioactive decay constant is always negative.
time = [natural log(ending amount / beginning amount)] / k
time = ln (20 / 24) / -.00011
time = ln (5/6) / -.00011
time = -.018232155683 / -.00011
time =
<span>
<span>
<span>
165.7468698455
</span>
</span>
</span>
time =
<span>
<span>
<span>
165.75 years
</span></span></span>
Answer:
Step-by-step explanation:
I believe that this is the answer.
They will have the same amount of money after 7 weeks.
We first set these equal to each other:
36+4x=x²+15
We want to gather all of the variables on one side. Subtract 4x from both sides:
36+4x-4x=x²+15-4x
36=x²-4x+15
We want the equation to be equal to 0 to solve it, so subtract 36 from both sides:
36-36=x²-4x+15-36
0=x²-4x-21
We can factor this expression. We want factors of -21 that sum to -4; -7(3)=-21 and -7+3=-4:
0=(x-7)(x+3)
Using the zero product property, we know that x-7=0 or x+3=0; this means x=7 or x=-3. Since a negative number of weeks makes no sense, the answer is 7 weeks.