57.14 A sound wave traveling downward with a speed of about 4,000 m/s suddenly slows to 1,500 m/s not far below the
Earth's surface.
What has the sound wave most likely encountered?
a different kind of rock
O an underground lake
an open cavity
O a pile of dinosaur bones

Anne applies a force on a toy car and makes it move forward. what can be said about the forces acting on the toy car at the moment anne applies the force?

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

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 ?