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» let after time t its inclination with horizontal is 45 at this time Vy /Vx =tan45 or Vy =Vx Vx remains constant =147cos60 =Vy now using equation of motion for verticle direction Vy=Uy-gt..........eq1 Uy=147sin60 ,Uy=147cos60 putting in eq 1, t=5.36 sec kindly elaborate your answer

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»

let after time t its inclination with horizontal is 45

at this time Vy /Vx =tan45 or Vy =Vx

Vx remains constant =147cos60 =Vy

now using equation of motion for verticle direction

Vy=Uy-gt..........eq1

Uy=147sin60 ,Uy=147cos60

putting in eq 1,

t=5.36 sec

kindly elaborate your answer