Question

Two 70-kg canoers paddle in a single, 50-kg canoe. Their paddling moves the canoe at 1.2 m/s with respect to the water, and the river they’re in flows at 4 m/s with respect to the land. What is their momentum with respect to the land?

a) 120 kg m/s,
b) 156 kg m/s,
c) 168 kg m/s,
d) 180 kg m/s

Answer 1

The momentum of the two canoers and the canoe with respect to the land is 988 kg m/s.

Step-by-step explanation:

The momentum of an object is defined as the product of its mass and velocity. The momentum of the two canoers and the canoe with respect to the land is 988 kg m/s. In this case, the combined mass of the two canoers and the canoe is 70 kg + 70 kg + 50 kg = 190 kg. The velocity of the canoe with respect to the land is the vector sum of its velocity with respect to the water and the velocity of the river with respect to the land.

Therefore, the velocity of the canoe with respect to the land is 1.2 m/s + 4 m/s = 5.2 m/s. The momentum of the canoe with respect to the land is calculated by multiplying the mass (190 kg) by the velocity (5.2 m/s), which gives a momentum of 988 kg m/s.