Projectile Motion: Given Horizontal Distance Travelled and Time Taken

[zenythz]

Okay, so we did an experiment in physics class where we launched a projectile from Point A (on the floor). The projectile obviously traveled in a parabolic motion and ended at Point B (on the floor again, so no difference in launching and landing heights).

We measured the distance from Point A to Point B to be 5 meters. We timed the projectile to find that it took 2 seconds to travel from Point A to Point B.

Here's my question: does dividing 5m by 2s give us overall initial velocity (v₀) or just the initial velocity of the horizontal component (v_0x)?

 

[ideasrule]

The 5m you measured was a horizontal distance, so 5m/2s can't possibly include any velocity in the y direction.

 

[tomcue]

Dividing 5m by 2s gives us the average horizontal velocity (vx) of the projectile. To determine the overall initial velocity (v0), we need to use the equation v0 = vx/cosθ, where θ is the angle of launch. This is because the initial velocity of a projectile has both horizontal and vertical components, and the overall initial velocity can be calculated using the horizontal velocity and the launch angle. Therefore, dividing the horizontal distance by the time taken only gives us the average horizontal velocity, not the overall initial velocity.