Help please :]!! please be right,

Mathematics

2 answers:

pickupchik [31]3 years ago

8 0

I think it’s c I had this question lol

Step2247 [10]3 years ago

4 0

It’s c ! gl on ur work ^^

You might be interested in

An ice cream cone has a height of 4 in and a radius of 1 in. If the cone is 0.1 in thick, what is the difference (in in3) betwee

SSSSS [86.1K]

Answer:

$0.79 in^3$

Step-by-step explanation:

Given data for the cone

height h= 4 in

radius r= 1 in

hence diameter d= 2 in

thickness of cone= 0.1 in

The volume of the cone including the shell can be expressed as

$volume=\frac{1}{3} \pi r^2h$

$volume= \frac{1}{3}*3.142*1^2*4\\\volume= \frac{12.568}{3} \\\volume= 4.189 in^3$

The volume of the ice cream can be expressed as

N/B: the diameter of the ice cream is

2-(0.1*2)= 2-0.2= 1.8 in

hence the radius is 0.9 in

$volume= \frac{1}{3}*3.142*0.9^2*4\\\ volume= \frac{10.18}{3} \\\ volume= 3.39 in^3$

The difference in volume is $4.189-3.39= 0.79 in^3$

8 0

3 years ago

A sample of tritium-3 decayed to 94.5% of its original amount after a year.

Zolol [24]

(a) If $y(t)$ is the mass after $t$ days and $y(0) = A$ then $y(t) = Ae^{kt}.$

$y(1) = Ae^k = 0.945A \implies e^k = 0.945 \implies k = \ln 0.945$

$\text{Then } Ae^{(\ln 0.945)t} = \frac{1}{2}A\ \Leftrightarrow\ \ln e^{(\ln 0.945)t} = \ln \frac{1}{2}\ \Leftrightarrow\ ( \ln 0.945) t = \ln \frac{1}{2} \Leftrightarrow \\ \\
t = - \frac{\ln 5}{\ln 0.945} \approx 12.25 \text{ years}$

(b)
$Ae^{(\ln 0.945) t} = 0.20 A \ \Leftrightarrow\ (\ln 0.945) t \ln \frac{1}{5}\ \implies \\ \\
t = - \frac{\ln 5}{\ln 0.945} \approx 28.45\text{ years}$