A projectile is fired from the ground at an angle of 30 degrees ...

[Hawke]

and it lands 150 meters away. Find (a) the initial velocity of the projectile and (b) the maximum height it reaches.

[coco]

Use the following equations:

Hmax = (v0^2*sin^2(theta))/2*g

R = range = (vo^2*sin(2*(theta)))/g

since the range is given, we can use it to find the initial velocity:

150*9.8 = vo^2*.866  so  vo^2 = 1697.46  and v0 = 41.2 m/s

Now use v0 to find the max height:

Hmax = 1697.46*.25/19.6 = 21.65 m

[Hawke]

Thanks It was right.