2.25m/s
Explanation:
Average velocity is the change in displacement of a bod with respect to time;
Velocity = Δd/Δt
velocity = d₂-d₁/Δt
Given d₂ = 12m, d₁ = 3m and Δt = 4s
Substitute the given value into the fromula;
velocity = 12-3/4
velocity = 9/4
velocity = 2.25m/s
Hence the seal's average velocity for the swim is 2.25m/s