A steel ball is fired vertically upwards with a velocity v. The ball reaches a height h. The same ball is now fired vertically upwards from the same position with a velocity 2v.
Air resistance can be ignored.
What is the new height reached by the ball?
A h
D 8h
B 2h
C 4h

Given,
v is the first velocity
h is the first height obtained.

According to equation of motion is a straight line:

v = u - 2gh (- since the ball is thrown against gravity)

v= -2gh — (i) (u is 0 since the ball is thrown from rest)

Now,
Let V be new velocity
Let H be new height obtained

According to the question:
V = 2v

Again from the equation of motion in straight line,

V = u - 2gH
2v = 0 - 2gH (ball is thrown from rest so u is 0)

From eq — (i):

2(-2gh) = -2gH
-4gh = -2gH

Therefore H= 2h ( Since, -2g & -4g cancel each other)

Hence the new height is twice the old height.