The discussion focuses on calculating the initial velocity of a projectile given its flight time and launch angle, specifically using the equations of motion. The key equations include Vix = Vcosθ and Vf = Viy + at, where Viy is determined using vertical motion principles. The correct initial velocity is found to be 15.2 m/s when considering the vertical component of motion at maximum height, where the final vertical velocity is zero. The discussion emphasizes the importance of analyzing vertical motion first to determine flight time accurately.
PREREQUISITESStudents and educators in physics, engineers working with projectile dynamics, and anyone interested in mastering the calculations involved in projectile motion analysis.
No. The projectile is always moving and its velocity is never zero. The equations that you have are valid from the time it starts moving until just before the projectile hits the ground.Asem said:can I say final velocity is equal to zero?
Good! Remember this for future reference: In projectile motion problems that give you the time of flight (or ask you to find the time of flight), always start with the equations for the vertical motion. That's because the value of g is what determines how long a projectile stays in the air.Asem said:Vf=0, when t=1s
Vf=Viy+at
Viy=9.8*1
Viy=Visin
9.8=Visin(40)
Vi=15.2
Thank you, sir
Yes.Asem said:I just have one more question; Vertical motion is symmetric in projectile right? So, is Initial velocity = Final velocity? If projectile is launched from ground level I mean.
No. When the projectile returns to the same level, the final speed is the same as the initial speed. The horizontal component of the velocity is the same while the final vertical component has the same magnitude but opposite direction from the initial component.Asem said:I just have one more question; Vertical motion is symmetric in projectile right? So, is Initial velocity = Final velocity? If projectile is launched from ground level I mean.