Help me figure out where this equation was derived

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SUMMARY

The discussion centers on deriving the equation for time (t) in projectile motion, specifically for a football kicked at an angle of 46.0° with an initial speed of 23.0 m/s from a distance of 36.0 m. The equation t = Δx / (vi * cos(θ)) is established from the basic principle of uniform motion, where Δx represents horizontal displacement and vi is the initial velocity. The horizontal component of the initial velocity is calculated using vi * cos(θ), which is essential for determining the time of flight in this context.

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Homework Statement



A placekicker must kick a football from a point 36.0 m (about 40 yards) from the goal, and half the crowd hopes the ball will clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 23.0 m/s at an angle of 46.0° to the horizontal.

I have completed the problem correctly but was told to find time by t= delta x / (vi *costheta)

Where is this equation derived from is what I'm asking?

thanks
 
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The time (t) it takes for something with uniform speed (u) to complete some displacement (\Delta x) is given by t=\frac{\Delta x}{u}. But the problem is that the uniform speed isn't quite the initial velocity of the ball. The ball is projected at an angle to the horizontal, so can you figure out what the horizontal velocity of the ball is?
 

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