Mass of the block = 1.4 kg
Weight of the block = mg = 1.4 × 9.8 = 13.72 N
Normal force from the surface (N) = 13.72 N
Acceleration = 1.25 m/s^2
Let the coefficient of kinetic friction be μ
Friction force = μN
F(net) = ma
μmg = ma
μg = a
μ = 
μ = 
μ = 0.1275
Hence, the coefficient of kinetic friction is: μ = 0.1275
Explanation:
A wave having a frequency of 200 Hz means that 200 such waves pass through a point per second.
There are 60 seconds in a minute.
This means that 5 minutes would be 60 times 5.
60×5 = 300
There are 300 seconds in 5 minutes.
Runoff because the mud is a liquid and moves on an amount of water that is in it like with quicksand