Projectile Motion Question (1 Viewer)

[cutemouse]

Hi all, I have another projectile motion question... Thanks if you can help me.

"A cannon ball is fired at 80m/s at an angle of 45 deg to the horizontal. Calculate the height at which the ball hits a verticle cliff 150m away"

Thanks,

Jason

 

[lolokay]

y = usin45 t - 1/2 gt²
sub in values and solve the quadratic to get t

x = ucos45*t
sub in values to get x

 

[cutemouse]

Hi,

For the quadratic results, which result is correct? (As you get two solutions)

Thanks,

Jason

 

[lolokay]

sorry, I did that wrong (we're solving for y, not x..)

x = ucos45*t
sub in values to get t

y = usin45 t - 1/2 gt²
sub in values to get y


that's what I had at first but changed it around for some reasons