Question

A body is projected vertically up with a velocity 98m/s after 2sec if the acceleration disappears the velocity of the body at the end of 3sec??

Answer 1

Please post question with all original punctuation.

Assuming the question is:
A body is projected vertically up with a velocity 98m/s. After 2sec, if the acceleration disappears, <i>what is</i> the velocity of the body at the end of 3sec??

From the question, it is interpreted that the body is projected with initial velocity of 98 m/s (on earth) and no further propulsion is applied, making it a vertical projectile.

After two seconds, the velocity is reduced to:
v1=v0-at=98-2*9.8=78.4.

If g is removed (by whatever means imaginable), then the body will continue at constant velocity v1=78.4 m/s upwards after 2 seconds until g is reinstated. (review Newton's first law).