Answer:
It takes 3 seconds to reach its high point
Explanation:
Projectile Motion
In a projectile motion (or 2D motion), the object is launched with an initial angle θ and an initial velocity vo.
The components of the velocity are
[tex]v_{ox}=v_o\cos\theta[/tex]
[tex]v_{oy}=v_o\sin\theta[/tex]
The speed in the horizontal direction at any time t is:
[tex]v_y=v_o\sin\theta-g.t[/tex]
The time taken to reach the maximum height is when vy=0, or:
[tex]\displaystyle t_m=\frac{v_o\sin\theta}{g}[/tex]
We are given the y-component of the velocity, thus:
[tex]\displaystyle t_m=\frac{30~m/s}{10~m/s^2}[/tex]
[tex]t_m=3~s[/tex]
It takes 3 seconds to reach its high point
