Recent content by Physicsrapper

isn't it c^2= r^2+h^2 ? r^2 = c^2 - h^2 Then I could substitute it: V = pi * (c^2-h^2) * h/3 then V = pi * ( (c^2h/3) - (h^3/3) ) V = pi * h/3 * (c^2 - h^2) derivative: pi * h/3 * d/dc (c^2 - h^2) = 2/3 * pi * h * c But this isn't the solution... What did I do wrong?

We only learned to make the derivative equal to zero in order to find it.

Mod note: Moved from technical math section, so is missing the homework template. A right triangle the hypotenuse of which is c revolves about a small side. A right circular cone is formed. Find the largest possible volume of the cone. Vcone: pi*r^2*(h/3)I don't get why they mentioned the...

"When your body runs out of glucose, it turns to fat for energy, which has 9 calories in every gram. This is a little more than double the amount in carbohydrates. Converting fat into energy takes longer than it does to convert glucose into energy, because fat must be first be broken down into...

I've read somewhere that 100 g of tomatoes have approximately 1 g protein, 2.6 g carbohydrates and 0.2 g fat. So it has 4*1 + 4*2.6 + 9*0.2 = 16.2 kcal A fried egg (~50 g) has 89 kcal, 4 g protein, 0.4 g carbohydrates, 6.7 g fat. So it has 4*4+4*0.4+9*6.7 = 77.9 kcal The sum of the kcals is...

How can I calculate the concentration of sulfuric acid with help of a neutralisation equation? (in mol/l or g/l) Neutralisation takes place with either NaOH or KOH. I've been searching for a tutorial for hours, but didn't find anything helpful. Could someone please explain me how to do it? I...

Cl2(g) + H2O(l) = HCl(aq) + HClO(aq) (reversible reaction) 1. What would happen to the concentration of HClO if more HCl was added? Wouldn't it decrease, since the position of equilibrium then would shift to the left? 2. If NaOH was added to neutralize the acid, what would happen to the...

A vertical spring with spring constant 300 N/m is compressed 0.06 m and a 0.25 kg ball placed on top. The spring is released and the ball flies vertically upward. What is the ball's speed when it has gone 0.1 m high? I don't know which relationship is required to find the speed, Can someone...

Find the value of the integral: a) ∫0π(sinx + 2)dx Formula I found: sin x dx = -cos x + C My calculation: F(x) = -cosx + 2x => (-cosπ + 2π)-(-cos0) = -1 + 2π + 1 = 2π , but the solution should be 2π +2 b) ∫02πsin(x/2)dx My calculation: F(x) = -cosx/2 => -cosπ + cos0 = 0 ; but the solution...

How to solve this: log(base16)x + log(base4)x + log(base2)x = 7 If I have log(base16)x for example and i make 10^(log(base16)x) of it, can I transform the base 16 into an exponent? It would look like that then: 10^(logx)^16 = x^16 Would that be correct? Then, I...

Suppose your pocket calculator is damaged: it can only evaluate logarithms of numbers between 0 and 1. Find a way to evaluate the following logarithms with the use of such a calculator. log2 = log (10*0.2) = log10 + log0.2 = 1 + log0.2 log333 = log(1000 * 0.333) = log10^3 + log0.333 = 3...

That gives me 66.6666666667 cm. But the solution should be around 2 cm. So something must be wrong with that equation, but what... ?

You mean, 10 000 km^3 / 150 mio km^2 But I can't divide something smaller by something bigger, or can I? I'm confused...

Volume of the sphere: 4/3*π*r^3 ---> is 10 000 km^3 the volume? Surface of the sphere: 4*π*r^2 ---> it's 4/3*π*6370^3 = 509.9 * 10^6 , isn't it? So I wanted to divide 10 000 km^3 by 509.9 * 10^6, but it doesn't funcion. What did I wrong?

10 000 cubic km of water can cover all the continents with a layer 7 cm deep. Find the depth of the water layer if 10 000 cubic km of water is spread over a sphere with radius R = 6370 km. ________________________________________________ My calculations: Volume of the sphere...