residents of hawaii are warned of the approach of a tsunami by sirens mounted on the tops of towers. suppose a siren produces a sound that has an intensity level of 120 db at a distance of 2.0 m.

Alead ball is dropped into a lake from a diving board 5m above the water . it hits the water with a certain velocity and then sink with constant velocity in bottom . it reaches the bottom 5 second after it is dropped if g= 10m/s2 . find depth of the lake and average velocity of the ball ?

How many atoms of nitrogen are in the chemical formula ni(w on

What kind of simple machine is a catapult?