Question

At time t=0,a bullet(A) is fired vertically upward with speed of 98 m/s.At t=5, bullet(B) is fired vertically upward with same speed. If air resistance is neglected then find the ratio of height of (A) w.r.t (B) above the ground at t = 12.5s

(a) 1: 2
(b) 1: 3
(c) 1: 1
(D) 1: 4

Answer 1

ANSWER

s=ut+21at2⇒98t−219.8t2=98(t−5)−219.8(t−5)2⇒t2−(t−5)2−100=0⇒10t=125t=12.5s

Now, total time for first arrow will be

s=ut+21at2⇒98t−219.8t2=0t(t−20)=0t1=20s⇒t2=25s

Now at t=20s

v=u+atv1=98&v2=9821v2v