# Projectile motion problem help

1. Jan 26, 2010

### jwang023

1. The problem statement, all variables and given/known data
An archer shoots an arrow horizontally at a target 16 meters away. The arrow is aimed directly at the center of the target, but it hits 57 centimeters lower.

What was the intitial speed of the arrow?

2. Relevant equations

3. The attempt at a solution

2. Jan 26, 2010

### rl.bhat

Why the arrow hit the lower point?
Here horizontal velocity of the arrow remains constant. But the vertical velocity increases starting with zero.
Can you find the time t taken by arrow to fall 57 cm lower?
This is the time taken by the arrow to hit the target. Distance of the target is known. Time is known. Find the initial velocity.