Q.

A projectile is thrown from a point O on the ground at an angle 45° from the vertical and with a speed 52 m/s. The projectile at the highest point of its trajectory splits into two equal parts. One part falls vertically down to the ground, 0.5 s after the splitting. The other part, t seconds after the splitting, falls to the ground at a distance x meters from the point O. The acceleration due to gravity g=10 m/s2. The value of t is  ______.         [2021]


Ans.

(0.50)

Range R=2uxuyg=2×5×510=5 m

Time of flight T=2uyg=2×510=1 s

 Time of motion of one part falling vertically downwards=0.5 s=T2

From law of conservation of momentum, Pi=Pf

       2m×5=m×vv=10 m/s

As there is no initial velocity in vertical direction for second particle, so it will also take same time as first one.

 Time of motion of another part, t=T2=0.5 s