Question

LAUPICS
Example 2. A tennis ball is thrown up a
reaches a height of 4.05 m before coming
down. What was its initial velocity? How
much total time will it take to come down
Assume g = 10 m/s2
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Answer 1

Answer:

ball is thrown up

hence v=O m/s

s=40.5 m

g= (-10)

v^2 = u^2 + 2gs

O. = u^2 + 2*(-10)*40.5

0. =. u^2 + (-81)

u^2 =. 81

u = 9 m/s

initial velocity 9m/s

s = ut + 1/2 gt^2

40.2 = o + 1/2 (-10)* t^2

40.2.=. (-5)* t^2

t^2. = 40.5/5

t^2. =. 8.1

t. = 9 s

total time = 9s + 9s

= 18 s