Answer:
dr/dt = -2 cm/s.
Explanation:
The volume of a cone is given by:
(1)
- r is the radius
- h is the height
Let's take the derivative with respect to time in each side of (1).
(2)
We know that:
- dh/dt = 10 cm / s (rate increasing of height)
- dV/dt = 0 (constant volume means no variation with respect of time)
- r = 4 cm
- h = 10 cm
We can calculate how fast is the radius changing using the above information.
Therefore dr/dt will be:

The minus signs means that r is decreasing.
I hope it helps you!
A hypothermia is like an idea and a theory is something you think
Answer:
2.17 Mpa
Explanation:
The location of neutral axis from the top will be

Moment of inertia from neutral axis will be given by 
Therefore, moment of inertia will be
![\frac {240\times 25^{3}}{12}+(240\times 25)\times (56.25-25/2)^{2}+2\times [\frac {20\times 150^{3}}{12}+(20\times 150)\times ((25+150/2)-56.25)^{2}]=34.5313\times 10^{6} mm^{4}}](https://tex.z-dn.net/?f=%5Cfrac%20%7B240%5Ctimes%2025%5E%7B3%7D%7D%7B12%7D%2B%28240%5Ctimes%2025%29%5Ctimes%20%2856.25-25%2F2%29%5E%7B2%7D%2B2%5Ctimes%20%5B%5Cfrac%20%7B20%5Ctimes%20150%5E%7B3%7D%7D%7B12%7D%2B%2820%5Ctimes%20150%29%5Ctimes%20%28%2825%2B150%2F2%29-56.25%29%5E%7B2%7D%5D%3D34.5313%5Ctimes%2010%5E%7B6%7D%20mm%5E%7B4%7D%7D)
Bending stress at top= 
Bending stress at bottom=
Mpa
Comparing the two stresses, the maximum stress occurs at the bottom and is 2.17 Mpa