Question

A boat is moving with a velocity 3i + 4j with respect to ground. the water in the river is moving with a velocity – 3i – 4j with respect to ground. the relative velocity of the boat with respect to water is

Answer 1

the answer will be 6i + 8j

Answer 2

Answer:  6 i + 8 j

Explanation:

Velocity of boat with respect to ground, Vb = 3 i + 4 j

Velocity of water in the river with respect to the, Vr = -3 i - 4 j

The relative velocity of the boat with respect,

Vbr = Vb - Vr

⇒Vbr =  3 i + 4 j - (-3 i - 4 j) = (3 +3) i + (4+4) j = 6 i + 8 j

The magnitude of the relative velocity of boat with respect to the river would be:

V = √6²+8² = 10