how do i find the height of a cylinder?

Question

the surface area of a cylinder S, having height h,and radius r,is S=pi r(r+2h) What is h when S=1.15m.sq, r=35cm

Answer 1

calculate the area of both ends (pi x radius squared) x 2

subtract this area from total surface area

then the area of the cylinder sides is height x circumferance

calculate circumferance (pi x diameter)

then divide the remaining surface area by the circumferance to get the height.

Answer 2

First Change the Surface area into cm. you get S=115 cm. and r=35cm. So now that you have like measurements plug them into your equation. 115= 35pi(35+2h). Divide by 35pi. 115/35pi=35+2h. Then you subtract 35 from both sides, then divide by 2. ((115/35pi-35)/2) But this gives you a negative number. If you have a radius of 35 cm. and a Surface area of 115 cm. It isn't possible. The area of the top of the cylinder itself would be 1225pi cm. Which is already larger than the surface area. Are you sure you typed in the question correctly?

Answer 3

The formula for the surface area of a cylinder is two times pi r squared (the areas of the two disks on top and bottom, plus 2 pi r times h for the smooth wall. Solve for h.

Answer 4

The surface area of a cylinder is actually described by 2pi times the radius times the height of the cylinder (2pi times the radius (r) is the circle circumference formula, and the circumference times the height gives the outer surface area of the cylinder). So if you have the surface area (S = 1.15m sq) and you have the radius (r = .35 m sq) then simply plug them into the formula.

S = 2pi times r times h
1.15meters squared = 2pi(.35meters)h
h = 1.15meters squared/2pi(.35meters)

h is expressed in meters since the top term is meters squared, and the bottom is meters.

By the way, cylinders do not have ends - they are open at each end...

Answer 5

You could do with stating whether the cylinder is open or closed at one or both ends.

The formula you give is for a cylinder that is open at one end.

Working off the formula you give

S = Pi r(r + 2h)
S = Pi r^2 + 2Pi rh
S - Pi r^2 = 2Pi rh

h = (S - Pi r^2)/(2Pi r)

Now making sure S and r have the same units, plug the values in.

You should get h = 34.794 cm

Answer 6

vol A/volB =625/5000 =125/1000 =5^3/10^3 ratio of lengths A/B = 5/10=1/2 10/h =1/2 h=20cm

Answer 7

Your formula for the surface area of a cylinder is incorrect. A cylinder has both a top and bottom.

Let
r = radius of cylinder
h = height of cylinder
S = surface area of cylinder

S = 2πr² + 2πrh = 2πr(r + h)

Solve for h

h = (S - 2πr²)/(2πr) = S/(2πr) - r

Now plug in the numbers.

h = 1.15/(2π*0.35) - 0.35 ≈ 0.1729 meters = 17.29 cm

Answer 8

S = ¶r (r + 2h) = ¶r² + 2¶rh

S - ¶r² = 2¶rh

(S - ¶r²)/2¶r = h

h = (1.15 - ¶ x 0.35 x 0.35) / (2¶ x 0.35)m
h = 0.348m = 34.8 cm

Answer 9

V = pr2 h

V/pir2= the height

Answer 10

S=pi r(r+2h)
1.15 = pi (0.35)(0.35+2h)
[1.15/(0.35pi)] - 0.35 = 2h
h = 0.348 m
h = 34.8 cm