You kick a soccer ball with a speed of 12 m/s at an angle of 21. How long does it take the ball to reach the top of its trajectory?

1 Answer
Feb 8, 2018

#0.4388 " seconds"#

Explanation:

#v_{0y} = 12 sin(21°) = 4.3 m/s#
#v = v_{0y} - g*t#
#"(minus sign in front of g*t because we take upwards velocity"# #"as positive)"#

#=> 0 = 4.3 - 9.8 * t" (at the top vertical velocity is zero)"#
#=> t = 4.3/9.8 = 0.4388 s#

#v_{0y} = " vertical component of the initial velocity"#
#g = " gravity constant "= 9.8 m/s^2#
#t = " time to reach the top in seconds"#
#v = " velocity in m/s"#