Physics Kinematics Level: High School
Relative Motion
The water current in a river moves relative to the land with a velocity vwl, and a boat is traveling on the river relative to the current with a velocity vbw.1) How is the velocity of the boat relative to the land (vbl) related to vwl , and vbw ?
2) Assume that the boat travels with a speed of 4.0 km/h relative to the current and that the current moves due east at a speed of 2.0 km/h relative to the land . Determine the velocity of the boat relative to the land for each of the situations described in items 2-4 .
A) Suppose that both the boat and the water current moves in the same direction and that ht boat is moving twice as fast as the current . Draw a vector diagram to determine the velocity of the boat relative to the land , vbl .
B) Suppose that the boat travels in the opposite direction of the current and that the boat is moving twice as fast as the current . Draw a vector diagram to determine the velocity of the boat relative to the land , vbl .
C) Suppose that the boat travels in a direction perpendicular to the current and that the boat is moving twice as fast as the current . Draw a vector diagram to determine the velocity of the boat relative to the land , vbl .
