A 5-kg fish swimming 1 m/s swallows an absent-minded 1-kg fish at rest. What is the speed of the large fish immediately after lunch? What would its speed be if the small fish were swimming toward it at 5 m/s?
2006-11-13 14:58:38 · 1 answers · asked by Melissa 2 in Education & Reference ➔ Homework Help
Melissa, this is another momentum question.
Momentum = mass x speed
The initial momentum of the large fish is 5 kg x 1m/s. This equals 5.
The initial momentum of the 1 kg fish is zero.
The final mass of the two fish is 5 + 1 = 6 kg.
Since the final momentum must equal the initial momentum (energy is conserved), the final momentum is 5.
So, 5 (the momentum) = 6 (the combined mass) x speed
Dividing both sides by 6 yields a speed of 5/6 m/s
You should be able to calculate the lasts part on your own.
2006-11-13 15:23:27 · answer #1 · answered by Doctor J 7 · 0⤊ 0⤋