Three Children are trying to balance on a seesaw, which consists of a fulcrum rock, acting as a pivot at the center, and avery light board 3.6 m long.

The heaviest invertebrate is the giant squid, which is estimated to have a weight of about 2 tons spread out over its length of 70 feet. What is its weight in newtons.

Water stands at a depth H in a large, open tank whose sidewalls are vertical. A hole is made in one of the walls at a depth h below the water surface.
a) at what distance R from the foot of the wall does the emerging stream strike the floor?
b) How far above the bottom of the tank could a second hole be cut so that the stream emerging from it could have the same range as for the first hole?

Assign a binary code in some orderly manner to the 52 playingcards. Use the minimum number of bits.

Here is problem, please help 

What is the equation of the line normal to ${\displaystyle f\left(x\right)=\frac{x\sin x}{\tan x}}$ at ${\displaystyle x=\frac{\pi }{3}}$?

Consider the surface given by the function $f(x,y)=\frac{4}{\sqrt{x^2+y^2-9}}$. What is the range of $f$? Determine any $y$-intercept(s) of $f$.
For range, I realize that $\sqrt{x^2+y^2-9}$ can be any number, so long as $x^2+y^2-9$ is positive or equal to zero. However, when looking at $f$, we know that the denominator cannot equal zero, which means that $\sqrt{x^2+y^2-9}$ can be any number greater than $0$. Would this mean that the range of $f$ is $(0,\mathrm{\infty })$?
For the $y$-intercept, I know that both $x$ and $z$ need to equal zero. Would this mean that there are no $y$-intercepts because $0$ is not in the range of $f$?

The 5 feet wall stands 28 ft froom the building. Find the length of the shortest straight beam that will reach to the side of the building from the ground outside the wall.