Answer:Take into account the the Earths gravity is 9.8 meters a second
Explanation:
Gravity pulls down on the ball at g=-9.81 m/s^2. Up is positive, down is negative.The ball started at a certain initial velocity of Vi m/s. Time it took is t=4s. Final velocity is Vf=0 m/s, because at the highest point the ball stops moving.
Vf=(g*t)+Vi
Rearrange for Vi.
Vi=Vf-(g*t)
Vi=0-(-9.81*4)=39.24 m/s (upward)
Think about it this way for the non-mathematical approach. The ball stops at the top. The initial velocity gets reduced by 9.81 m/s every second, and reaches 0 m/s at the top. It took 4 seconds, so 9.81*4 is equal to the initial upward velocity.
At 10 m/s, it will take
(2 m)/(10 m/s) =
0.2 sto bridge the gap.
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However, it will take an additional 0.514 seconds (0.714 s total) for the policeman to land on the building below. The answer depends on the meaning of the question.
Accelerated motion such as a vehicle (car) or a moving item such as a (football thrown in the air)