Question

A projectile is fired at a speed of 100 m/s at an angle of ${37}^o$, above horizontal.At the highest point, the projectile breaks into two parts of mass ration 1:3 the similar coming to rest, then the distance between launching point and the point where the heavier piece lands:

• A. 480 m
• B. 960 m
• C. 1120 m
• D. 640 m

Answer 1

Answer: (C)

1120 m

Velocity of projectile at highest point $=100\left(\cos 37°\right)80m/s$

Mass $=4m$ heavier particle $=3m$

Also, $3mv=4m\left(80\right)=320mv=320m/s$

Now, let the height at which projectile break $=h$

$\therefore h=(100\sin 37°{)}^2/2g=180m$

Times taken to reach ground $\sqrt{\frac{2h}{g}}=\sqrt{36}=6sec$

Horizontal distance travelled by $3m=\left(320/8\right)\times 6=640m$

Horizontal distance travelled by $4m=80\times 6=480m$

Total $640m+480m=1120m$