A body is projected up reaches a point A in its path at the end of the 4th second and reaches the ground after 5 seconds from the rest.the height of A above the ground is?

Question

pythagoras123 · Answer

Can it be assumed the ball is at rest at point A?

partyshotz2409 · Answer

y = -1/2 * 10*t^2 + u*t 

given t = 5  , y = 0

y(5) = 0
y(5) = -125 + 5u 

substitute
-125 + 5u = 0 
5u = 125
u = 125/5 
u = 25

y = -1/2 * 10*t^2 + 25*t 
plug in t = 4
y(4) = 20 

at 4 seconds the object is 20 meters above ground

drmoss · Answer

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