A sign means the water isn't safe for a head-first entry.

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 ?

Explain what happens at the saturation point when adding salt to water at room temperature.

How many neutrons does plutonium -196 with an atomic number of 78.