How to calculate horizontal distance traveled by meteor given altitude, speed and downward velocity?

So, it's starts at an altitude of 60km. If it's downward velocity is 0.5km/sec, then it will be airborne for 60km / 0.5km/sec = 120 seconds. If it's horizontal speed is 6km/sec, and it's off the ground for 120 seconds, then 6km/sec X 120secs = 720km.

This is more a physics question than an astronomy question, but we'll help out. If you know the speed and downward (i.e. vertical) velocity, you can easily obtain the horizontal velocity because you've already learnt the Pythagoras theorem in school and you already learnt vector addition. Also, if you know the starting altitude and the vertical velocity, you can obtain how long it takes to hit the ground starting from that initial altitude; you can ignore gravity because the velocities are quite high for Earth's gravity to make significant changes (meters per second is very small compared with kilometers per second) therefore it's a constant-velocity motion (no acceleration). Try again with those suggestions and let us know if you're still having trouble.

You would have to calculate how long it takes for the downward velocity to bring the meteor to the ground. You would then have to calculate how far the meteor could go in its sideways motion in that amount of time.

This is more a physics question than an astronomy question, but we'll help out. If you know the speed and downward (i.e. vertical) velocity, you can easily obtain the horizontal velocity because you've already learnt the Pythagoras theorem in school and you already learnt vector addition. Also, if you know the starting altitude and the vertical velocity, you can obtain how long it takes to hit the ground starting from that initial altitude; you can ignore gravity because the velocities are quite high for Earth's gravity to make significant changes (meters per second is very small compared with kilometers per second) therefore it's a constant-velocity motion (no acceleration). Try again with those suggestions and let us know if you're still having trouble.

You would have to calculate how long it takes for the downward velocity to bring the meteor to the ground. You would then have to calculate how far the meteor could go in its sideways motion in that amount of time.