Answer:
fo = 378.52Hz
Explanation:
Using Doppler effect formula:

where
f' = 392 Hz
C = 340m/s
Vb = 20m/s
Va = 31m/s
Replacing these values and solving for fo:
fo = 378.52Hz
0J
According to the law of conservation of energy, the potential energy is converted to kinetic energy. Remember, potential energy is calculated using height and weight. If the ball is on the ground, height is 0.
<span>Copper is a good conductor of electricity because its atoms have a loosely held electron in their outer shell that is able to move freely to other atoms.</span>