Question

a bullet is fired upwards with the initial velocity of 250m/s. determine the time taken to reach the maximum height

Answer 1

using:

v = u - gt.

Where v = final velocity in m/s, u = initial velocity in m/s, g = acceleration due to gravity in m/s², t = time in s.

At maximum height the final velocity v = 0 m/s. u = 250 m/s

v = u - gt.

0 = u - gt.

gt = u

t = u / g g ≈ 9.8 m/s²

t ≈ 250 / 9.8

t ≈ 25.51

Time to reach maximum height is ≈ 25.51 seconds.

Answer 2

the final velocity is 0 and the acceleration is gravity. Vf=Vi+at because gravity opposes the motion it will be -g
0=250-gt
gt=250 ....g=10
t=25sec