physics question::?

Question

A soccer ball is kicked with a speed of 10.50 m/s at an angle of 20.0° above the horizontal. If the ball lands at the same level from which it was kicked, how long was it in the air? (Neglect air resistance.)

Answer 1

These types of motion always get solved using
v(t)=v0-g*t
When v(t)=0, the object is at apogee, and half-way through the flight.

in this case
v(t)=10.50*sin(20)-g*t
t at apogee is
10.50*sin(20)/g

Another way to solve it is to look at t when v=-v0, which is when the object strikes the ground
or
-10.50*sin(20)=10.5*sin(20)-g*t
t=2*10.50*sin(20)/g

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