Question

Ball thrown vertically upwards with an initial velocity of 19.6m/s returns 4s later. Greatest height reached by the ball will be

Answer 1

• initial velocity=u=19.6m/s
• Acceleration due to gravity=g=10m/s^2
• Time=t=4s
• Height=h

According to second equation of kinematics

$\boxed{\sf h=ut+\dfrac{1}{2}at^2}$

$\\ \sf\longmapsto h=19.6(4)+\dfrac{1}{2}\times 10(4)^2$

$\\ \sf\longmapsto h=78.4+5(16)$

$\\ \sf\longmapsto h=78.4+80$

$\\ \sf\longmapsto h=158.4m$