Question

a ball rolls off a table and hits the floor at 5m/s. what is the height of the table.....

PLEASE FAST......

Answer 1

Dear Student, 
When a ball rolls off a table, the time it takes to hit the floor is a function of the height of the table only and it does not depend on the speed. 


T =
$\sqrt{2h \gamma g$

Answer 2

here velocity of the ball when it hit the ground
v = 5 m/s, let height be h
using third equation of kinematics
${v}^{2} - {u}^{2} = 2gh$
$h \: = \frac{ {v}^{2} - {u}^{2} }{2g}$
$h \: = \frac{ {(5m { s}^{ - 1}) }^{2} - {0}^{2} }{2 \times 9.8m {s}^{ - 2} } = 1.28 m$