need help to find angle

[sonicflare9]

Over a completely flat surface a ball weighing 0.8kg is thrown with a speed of 50m/s
what angle must it be thrown at to land 100m away

 

[skeeter]

need help finding the angle

Over a completely flat surface, a ball weighing 0.8kg is thrown with a speed of 50m/s. What angle must it be thrown at to land 100m away?

mathforums.com

 

[Oiler]

I take it the entirety of the ball’s motion happens on a flat plane, in which case you know that the vertical displacement of the ball is [MATH]0m[/MATH], in addition to the fact that the horizontal displacement is [MATH]100m[/MATH]. can you form equations for the horizontal and vertical displacement in terms of [MATH]\theta[/MATH] and [MATH]t[/MATH] ? (You will end up with simultaneous equations for which you can substitute t in terms of theta)

I’m not seeing the relevance of the ball’s mass in its projectile motion though, unless it’s heavy enough to influence the motion of the earth appreciably. I’m 90% sure the mass given just to confuse you.