At what speed a ball must be projected vertically upward so that dista...
Calculation of Velocity Required for Ball Projection
Let us consider the motion of the ball projected vertically upward.
Distance Traveled by Ball
Let us assume that the ball is projected upward with an initial velocity u. The distance traveled by the ball in the nth second can be given by:
sn = u + (u-g) + (u-2g) + ... + [u-(n-1)g]
where g is the acceleration due to gravity.
Therefore, the distance traveled by the ball in the 5th second can be given by:
s5 = u + (u-g) + (u-2g) + (u-3g) + (u-4g)
And the distance traveled by the ball in the 6th second can be given by:
s6 = u + (u-g) + (u-2g) + (u-3g) + (u-4g) + (u-5g)
Equating Distances Traveled in 5th and 6th Second
Now, we have to equate the distances traveled by the ball in the 5th and 6th second:
s5 = s6
u + (u-g) + (u-2g) + (u-3g) + (u-4g) = u + (u-g) + (u-2g) + (u-3g) + (u-4g) + (u-5g)
On simplifying, we get:
u = 25g/2
Therefore, the ball must be projected vertically upward with a velocity of 25g/2 in order to travel the same distance in the 5th and 6th second.