17. A projectile is projected in the upward directionSmaking an angle of 60° with the horizontal directionwith a velocity of 147 ms 1. After what time will itsinclination with the horizontal be 45?

17. A projectile is projected in the upward directionSmaking an angle

1.	17. A projectile is projected in the upward directionSmaking an angle of 60° with the horizontal directionwith a velocity of 147 ms 1. After what time will itsinclination with the horizontal be 45?
Answer» <p>let after time t its inclination with horizontal is 45</p><p> at this time Vy /Vx =tan45 or Vy =Vx</p><p> Vx remains constant =147cos60 =Vy</p><p> now using equation of motion for verticle direction</p><p> Vy=Uy-gt..........eq1</p><p> Uy=147sin60 ,Uy=147cos60</p><p>putting in eq 1,</p><p> t=5.36 sec</p> <p>kindly elaborate your answer</p>