The table below shows four wave sources. Green laser
Tuning fork
UV lamp
Megaphone
The waves enter the testing box through the opening. Inside the testing box are three sections. The air and water sections are separated by a transparent glass
pane. The water section and the vacuum chamber are separated by a transparent plastic pane. Which sources will be detected?

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.