Question

Given a body, of negligible weight, initially a point (20,30) in the SI convention on the x-y plane, is fired at 400m/s at an angle of 60degrees(to the vertical). What coordinates will the body assume after 30sec of travel

Answer 1

The horizontal and vertical components of velocity:

$$v_x=v\sin\theta,\\ v_y=v\cos\theta.$$

The x-coordinate after 30 s:

$$x=x_0+v_xt=x_0+vt\sin\theta=10412\text{ m}.$$

The y-coordinate:

$$y=y_0+v_yt-\frac{gt^2}2=y_0+vt\cos\theta-\frac{gt^2}2=1620\text{ m}.$$