Question

A fixed mortar fires a bomb at an angle of ${53}^{\circ }$ above the horizontal with a muzzle velocity of $80$ $m{s}^{-1}.$ A tank is advancing directly towards the mortar on level ground at a constant speed of 5 m/s. The initial separation (at the instant mortar is fired ) between the mortar and tank, so that the tank would be hit is (Take $g=10m{s}^{-2}$)

• A. 662.4 m
• B. 526.3 m
• C. 486.6 m
• D. None of these

Answer 1

The correct option is D None of these

time taken and range for projectile is

$t=\frac{2usin\theta }{g}=16sin{53}^o$

$R=\frac{u^{2}sin2\theta }{g}=640sin{106}^o$

The initial separation d should be equal to the range of mortar plus the distance traveled by tank.

$d=5\times 16sin{53}^o+640sin{106}^o=5\times 0.8+640\times 0.96=618.4m$