Question

With what speed should a body be thrown upwards so that the distance in 5th and 6th secomd is same

Answer 1

10m/s will be the speed of the body

Answer 2

"Given condition of being the 5th and 6th second distance to be equal can only be attained when the 5th is the ascent and 6th be the descent in a flight of projectile corresponding to each other within the time and distance frame over the path acquired.

Solution:

Thereby, assume that the motion of 5th second is the motion of projectile to attain the maximum height where the final velocity becomes zero and then descent starts in 6th sec.

Thereby,

Applying the equation of motion for this condition, we have,

v = u + at

Where, v = 0

u = 0 - gt

u = -5g

u = -49 m/s

Negative sign indicates that the force is applied against the gravitational force."