Answer
given.
Mass of big fish = 15 Kg
speed of big fish = 1.10 m/s
mass of the small fish = 4.50 Kg
speed of the fish after eating small fish =?
a) using conservation of momentum
m₁v₁ + m₂v₂ = (m₁+m₂) V
15 x 1.10 + 4.50 x 0 = (15 + 4.5)V
16.5 = 19.5 V
V = 0.846 m/s
b) Kinetic energy before collision
[tex]KE_1 = \dfrac{1}{2}m_1v_1^2 + \dfrac{1}{2}m_2v_2^2[/tex]
[tex]KE_1 = \dfrac{1}{2}\times 15 \times 1.1^2 + \dfrac{1}{2}m_2\times 0^2[/tex]
KE₁ = 9.075 J
Kinetic energy after collision
[tex]KE_2= \dfrac{1}{2}(15+4.5)\times 0.846^2 [/tex]
KE₂ = 6.98 J
Change in KE = 6.98 - 9.075 = -2.096 J
hence,
mechanical energy was dissipated during this meal = -2.096 J
