If a motorboat travels 25km/h towards the sea, down a river whose velocity is 4km/h what is the boats velocity related to the shore?

V = 25 + 4 = 29 km/h.

To find the boat's velocity related to the shore, we need to consider the effect of the river's velocity on the boat's motion. Since the boat is traveling against the river's flow, the river's velocity will subtract from the boat's velocity.

Here's how you can calculate it:

1. Determine the boat's velocity: The boat's velocity is given as 25 km/h towards the sea.

2. Determine the river's velocity: The river's velocity is given as 4 km/h.

3. Subtract the river's velocity from the boat's velocity: Since the river flow is in the opposite direction to the boat's motion, we subtract the river's velocity from the boat's velocity.

Boat's velocity related to the shore = Boat's velocity - River's velocity

Boat's velocity related to the shore = 25 km/h - 4 km/h

Boat's velocity related to the shore = 21 km/h

Therefore, the boat's velocity related to the shore is 21 km/h.