Question

A 1235 kg whale swims horizontally at a speed of 6.4 m/s. It suddenly collides directly with a stationary seal of mass 189 kg. The seal grabs onto the whale and holds fast. What is the speed of these two sea creatures just after their collision?

Answer 1

The speed of these two sea creatures just after their collision is 5.55 m/s.

Step-by-step explanation:

Given;

mass of the whale, m₁ = 1235 kg

initial speed of the whale, u₁ = 6.4 m/s

mass of the seal, m₂ = 189 kg

initial speed of the seal, u₂ = 0

let their final speed after collision, = v

Apply the principle of conservation of linear momentum;

m₁u₁ + m₂u₂ = v(m₁ + m₂)

(1235 x 6.4) + (189 x 0) = v(1235 + 189)

7904 = 1424v

v = 7904 / 1424

v = 5.55 m/s

Therefore, the speed of these two sea creatures just after their collision is 5.55 m/s.