Question

an object projected vertically up from the tower took 5s to reach the ground. If the average velocity of object is 5m/s,find it's average speed

Answer 1

let say your object reached at certain height when thrown up


lets 1 st calculate time to reach the highest point V=u+at


0=5-10t. ......g=10

final velocity is 0 at top g is negative

t=0.5 s..............(1)

lets find H upto which object reached.


v^2=u^2+2as

0=25-20s

s=1.25m...........(2)


total time is 5sec

time requred to reach the object to ground from top to bottom is
=5-0.5
=4.5sec..........(3)


lets calculate height reach to ground


avg vel =
$\frac{distance}{time max \: to \: ground}$
distance fron max to ground = 22.5m
..........(4)


average speed =
$\frac{total distance}{time}$
= (22.5+1.25)/5

=4.75m/s