A motor boat is sailing along the river River speed = 1.5 m / s, boat speed = 2 m / s

A motor boat is sailing along the river River speed = 1.5 m / s, boat speed = 2 m / s. What is the modulus of speed if it moves with the flow.

For a complex movement of a motor boat, its absolute speed will be equal to the vector sum of the relative and portable speeds, since the motor boat moves relative to another system (river flow).
Va = Vr + Vt, where Vr is the motor boat’s own speed (Vr = 2 m / s), Vt is the river flow speed (Vt = 1.5 m / s).
Va = Vr + Vt = 2 + 1.5 = 3.5 m / s.
Answer: The speed module of a motor boat is 3.5 m / s.