I have three problems that I need help with,

I used the disk method and found the volume to be , can somone verify please?1.

The area under the curve from to is revolved about the x-axis. Calculate the volume of the surface of revolution.

As well I have not had a problem like this before. I found the slope though to be and the equation of the line to be . I suppose i am to either derive the equation or integrate, but i don't have a clue.2.

Suppose an object is moving along with this curve. When the object arrived at (1,1) it was moving up with a speed of 4m/s. Calculate the speed and direction of the motion horizontally.

d = 20m3. A boy is 20m away from a rising balloon. The angle of elevation is increasing at a rate of 3 degrees/sec. At the instant the balloon is 8m above the ground find its speed of ascent.

= 3 deg/sec

? when h = 8m

I do not know what equation i would be using, i tried using and my answer was 69.6m/s but i think that is wrong.

Help appreciated very much.