#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"#