Question #d545d

1 Answer
Jan 11, 2017

The components will be

#v_x=(25)cos(-35°) = 20.5 m/s#


#v_y=(25)sin(-35°) = -14.3 m/s#


Under ideal conditions of zero air resistance, the path of the projectile is a parabola. The symmetry of this path tells us that at any two points in the path of the potato, when it is at the same elevation, its speed will be the same, and the direction will be at an identical angle, only negative rather than positive.

In other words, if the potato left the ground at 25 m/s and an angle of 35° above the horizontal, it will return to the same elevation travelliing again at 25 m/s but at an angle of -35° (35° below the horizontal).
Realizing this can save you a lot of (unnecessary) calculations!

So, all we need do is find the components of this velocity:

#v_x=vcos theta=(25)cos(-35°) = 20.5 m/s#

#v_y=vsin theta=(25)sin(-35°) = -14.3 m/s#