Catapult Projectile Question wow

[dkbuono]

Homework Statement

Catapult
A catapult on a cliff launches a large round rock towards a ship on the ocean below. The rock leaves the catapult from a height H = 35.0 m above sea level, directed at an angle theta = 48.7° above the horizontal, and with a speed v = 26.1 m/s. Assuming that air friction can be neglected, calculate the horizontal distance D traveled by the projectile.

Homework Equations

y=y0+Vy0t-1/2gt^2
x=x0+ Vx0t

The Attempt at a Solution

Ok, So I plugged in my knowns to find the time for this, using the first equation setting it up like this 4.9t^2-19.6t+35, where vy0t=26.1*sin48.7 gave me 19.6 then I plugged in my values to the Quadratic formula where the answers I got were 2.97 and 1.03 respectively to find time, so I use the lower of the two numbers and I plug it back into x=x0+Vx0t, since intial D is 0 you add 26.1*cos(48.7) to give 17.2 then you times it to the time calculated 1.03 to get 17.72 m...its not right, I don't understand where I am going wrong I've set it up 7 different ways... This seems like a relatively easy question I only have 2 more tries left on it out of 10. Would someone point me in the right direction I am getting frustrated at this point and feel like and idiot considering its only ch.2.

 

[LowlyPion]

I would recalculate your quadratic

4.9t^2-19.6t+35

Only this time I would use 4.9t² - 19.6t - 35 = 0

You might get a better result.

 

[dkbuono]

LowlyPion thank you so much you were right that simple error completely distorted everything! :)

 

[LowlyPion]

LowlyPion thank you so much you were right that simple error completely distorted everything! :)

I got very suspicious when I saw the solution had 2 imaginary answers.

Glad it worked out.

Good Luck.

 

[__JR__]

I got very suspicious when I saw the solution had 2 imaginary answers.

I'm going to have to write that one down.