A ball is thrown vertically upward with a velocity of 100m/s.It will reach the ground after hw many sec?

2 answers

The total time in the air is twice the time it takes for the ball to decelerate to 0 m/s (at the mazximum height). That time equals 2Vo/g, where Vo is the initial velocity.

That would be 20.4 seconds.

The maximum height reached would be 1020 m. A human cannot throw a ball that fast. The question is unrealisttic. Aerodynamic resistance would be appreciable.

100 m/s is 328 miles/hour, nearly half the speed of sound.
Take the values....V=om/s..U=100m/s...a=g=-10m/s(since it is against the gravity)..t=?....Using 1st kinematic equation i.e. V=U+at...putting all the values....0=100+(-10)t... -100=-10t....t=-100/-10..t=+10 sec.....since total time equals time taken going up nad going down...therefore t=10+10.....t=20sec.