Hi. The language here looks as though it's Spanish/Portugese ??? It would help to answer the q if the q were posted in english. I speak a little spanish and french, but it's mostly guesswork.
Answer:
v = 14.32 m/s
Explanation:
According to the principle of conservation of linear momentum, both the momentum and kinetic energy of the system are conserved. Since the two balls are in the same direction of motion before collision, then;
+
= (
+
) v
0.035 × 12 + 0.120 × 15 = (0.035 + 0.120) v
0.420 + 1.800 = (0.155) v
2.22 = 0.155 v
⇒ v = 
= 14.323
The velocity of the balls after collision is 14.32 m/s.
Answer:
A modern piano has 88 keys and is tuned to twelve-tone equal temperament. It has its 49th key, the fifth A, also called A4, tuned to a frequency of 440 Hz (referred to as A440).