A projectile is fired at an angle 30° to the horizontal such that the vertical component of its initial velocity is 80 m/s. Find approximately the velocity of the projectile at time T/4 where T is time of flight.

Question

A projectile is fired at an angle 30° to the horizontal such that the vertical component of its initial velocity is 80 m/s. Find approximately the velocity of the projectile at time T/4 where T is time of flight. (A) 180 m/s (B) 155 m/s (C) 145 m/s (D) 140 m/s

Tardigrade Admin · Accepted Answer

u sin 300 =80 ⇒ u=160 m/s ux =u cos 30° =160 (√3/2) =80√3 m/s T= (2u sin 30°/g) =(2 × 80/10) =16 s vy =uy -g (T/4) =80 -(10×16/4)=40 m/s v=√v2x+v2y =√(80√3)2 +402 =145 m/s

Q. A projectile is fired at an angle 30∘ to the horizontal such that the vertical component of its initial velocity is 80m/s. Find approximately the velocity of the projectile at time T/4 where T is time of flight.

180 m/s

155 m/s

145 m/s

140 m/s

usin300=80 ⇒u=160m/s ux​=ucos30∘=16023​​=803​m/s T=g2usin30∘​=102×80​=16s vy​=uy​−g4T​=80−410×16​=40m/s v=vx2​+vy2​​ =(803​)2+402​=145m/s

Q. A projectile is fired at an angle $3 0^{\circ}$ to the horizontal such that the vertical component of its initial velocity is $80 m / s$ . Find approximately the velocity of the projectile at time $T /4$ where T is time of flight.