A motorboat travels at a speed of 40 km/h relative to the surface of the water. If it travels upstream against a current of 12 km/h what is the boats speed relative to the shore?

To find the boat's speed relative to the shore, we need to consider the effect of the current.

When the boat travels upstream against the current, its actual speed relative to the shore decreases. This is because the current is working against the boat's forward motion, effectively reducing its speed.

To calculate the boat's speed relative to the shore, we can use the concept of relative velocity. The boat's speed relative to the shore can be found by subtracting the speed of the current (12 km/h) from the boat's speed relative to the water (40 km/h).

So, the boat's speed relative to the shore is:
40 km/h - 12 km/h = 28 km/h

Therefore, the boat's speed relative to the shore is 28 km/h.