How do you find velocity when you know height?

For objects in free fall or projectile motion, use:

v = √(2gh)

where g is gravitational acceleration (9.8 m/s²) and h is height. This gives the velocity just before impact.

Step-by-step calculation:

• Multiply height by 2: 2 × h
• Multiply result by g (9.8 m/s²)
• Take the square root of the result

Example: A ball dropped from 20 meters has final velocity = √(2 × 9.8 × 20) = √392 ≈ 19.8 m/s.