Trajectory of particle in a projectile motion is given as y = x - x280 .
Here , x and y are in meters. For this projectile motion match the following with g = 10 m / s2
"coloumn1coloumn2(a)Angle of Projection(p)20(b)Angle of velocity with horizontal after 4s(q)80(c)Maximum Hieght(r)45∘(d)Horizontal Range(s)tan−112 "
Comparing with the standard equation of projectile,
y = x tan θ - gx22u2cos2θ
We get , θ = 45∘ and u = 20 √2 m/s
Time period of this projectile is 4s . Hence after 4s velocity vector will again make 45∘ with horizontal