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.
The formula to find the initial velocity (v0) of a projectile given the flight time (T) and launch angle (θ) is v0 = (g * T) / (2 * sin(θ)), where g is the acceleration due to gravity (approximately 9.81 m/s²).
The derivation starts with the fact that the total flight time T is the time for the projectile to go up and come back down. Using the vertical motion equation, T = (2 * v0 * sin(θ)) / g, solving for v0 gives v0 = (g * T) / (2 * sin(θ)).
The units should be consistent: time (T) in seconds (s), acceleration due to gravity (g) in meters per second squared (m/s²), and the angle (θ) in degrees or radians. The initial velocity (v0) will then be in meters per second (m/s).
Yes, the initial velocity can be found if the angle is given in degrees. However, you must convert the angle from degrees to radians by using the conversion factor π/180. For example, θ in radians = θ in degrees * (π/180).
If the launch angle is 90 degrees, the projectile is launched vertically. In this case, the initial velocity formula simplifies to v0 = g * T / 2, since sin(90°) = 1.