Answer
No
Work Step by Step
The bottle that has fallen off the board, has some velocity, and the velocity of the boat with respect to that bottle is equal to 5m/s.
But since the bottle has a velocity with respect to the ground too, the velocity of the boat with respect to the bottle is boat is not equal to the velocity of the boat with respect to the ground.
To find the velocity of the boat with respect to the ground, we need to add up the velocity of bottle with respect to ground and the velocity of the boat with respect to the bottle.
