M # 2

The diagonals of a rhombus are 10 cm and 24 cm. What is (i) the perimeter of the rhombus? (ii) area of the rhombus?

m#2 perimeter:4.13=52
area:240

M # 3 : krassi_holmz, you're correct! The answer is 13 m.
M # 2 : Perimeter = 52 m, correct! Area=?
M # 1 : Try again

M # 1 (and here's a b to put the post back in the natural key. )

The cone has a volume of 1/3πr²h.
The hemisphere has a volume of 2/3πr³.
The cylinder has a volume of πr²h.

r = h, so the hemisphere's volume can be written as 2/3πr²h.

Taking out all of the common factors gives ratios of 1/3:2/3:1.

Scaling this up makes the ratios 1:2:3.

M # 4

A spherical iron ball is dropped into a cylindrical
vessel of base diameter 14 cm, containing water. The water
level is increased by 9  1/3 cm. What is the radius of the ball?

I edited your post to include π. To write pi as a symbol, just stick a : in front of it.

You're right about the volume of the sphere, although it would be easier to leave it as 7²*π*9 1/3.

This has to equal 4/3πr³.

The π's cancel out, and you can divide by 4/3 on each side to get 7²*7 = r³.

And that makes the radius of the sphere 7cm.

M # 5

How many metres of cloth 11m wide would be required to make a conical tent of base radius 7m and height is 24m?

Well done, irspow!

M # 7

Water flows through a cylindrical pipe of internal radius 3.5 cm at 5m per second. Calculate the volume of water in litres discharged by the pipe in one minute.