Answer:
Time, t = 0.439 seconds
Step-by-step explanation:
Given the following data;
Angle, x = 21°
Initial velocity, u = usinx = 12Sin21° = 4.3004m/s
We know that acceleration due to gravity is equal to 9.8m/s
Final velocity = 0m/s since it reached its highest trajectory.
To find the time, we would use the first equation of motion;
V = U + gt
0 = 4.3004 + (-9.8)t
0 = 4.3004 - 9.8t
9.8t = 4.3004
t = 4.3004/9.8
t = 0.439 seconds
Therefore, it will take the ball 0.439 seconds to reach the top of its trajectory.