Final answer:
a. The force of the water on the boat is 2.18 x 10³ N in the opposite direction to the motor's force.
b. The net force on the boat is zero, as it is moving at a constant velocity.
c. Therefore, the boat's speed will remain at 7.9 m/s after 3 seconds.
Step-by-step explanation:
The question involves a boat moving through water with a constant velocity while being acted upon by two forces. The physics concepts relevant to this question are Newton's laws of motion, particularly the first law, which states that an object at constant velocity has no net force acting on it, and the second law, which relates force, mass, and acceleration. Given that the boat is moving at a constant velocity:
- (a) The force of the water on the boat is equal and opposite to the force exerted by the motor, which is 2.18 × 10³ N in the reverse direction, assuming no other forces are acting on the boat.
- (b) The net force acting on the boat is zero since the boat is moving at a constant velocity.
- (c) The speed of the boat at the end of 3 seconds will remain at 7.9 m/s, as there is no unbalanced force acting on the boat to change its velocity.