Question

a projectile is thrown in a horizontal plane such horizontal velocity is 9.8 and vertical velocity is 19.6 m/s respectively,it will strike the plane after covering a distance of___?? anyone help..

Answer 1

you can decompose the motion in two directions: vertical and horizontal.
in horizontal direction the object experiences no force(no acceleration) so its horizontal motion is with constant speed, so the distance d would be:
\[d=v_h*t\]
in vertical direction the time that it takes to reach the max hight could be derived from equation:
\[v=v_v - g t\]
but the vertical velocity at max hight is 0 so
\[0=v_v-g t \rightarrow t=\frac{ v_v }{ g }\]
the situation is completly simetric so the time that it takes for the object to reach the ground is two times time to reach max height
so
\[d=\frac{ 2v_vv_h }{g }\]
for our given it's
\[d=\frac{ 2*19,6*9,8 }{ 9,8 }=39,2m\]