A 63 kg canoeist stands in the middle of her 22kg canoe. The canoe is 3m long, and the end that is closest to land is 2.5m from the shore. The canoeist now walks toward the shore until she comes to the end of the canoe.

suppose the canoeist is 3.4 m from the shore when she reaches the end of her canoe. What is the canoe's mass?

Look at the first sentence of your question. They have already told you the canoe's mass.

I know that ,, but I don't think the will give this kind of stupid question to a first year college student. I only know that it is a center of mass equation !

To find the mass of the canoe, we can use the principle of conservation of momentum.

The momentum of an object is defined as the product of its mass and velocity. In this case, we can consider the canoeist and the canoe as a system with initial momentum equal to zero. When the canoeist walks towards the end of the canoe, she imparts a momentum to the system. We can use this change in momentum to determine the mass of the canoe.

First, we need to determine the initial momentum of the canoeist and the canoe system. The total mass of the system is the sum of the mass of the canoeist and the mass of the canoe:

Total mass (initial) = Mass of canoeist + Mass of canoe
Total mass (initial) = 63 kg + 22 kg = 85 kg

Next, we need to determine the final momentum of the system when the canoeist reaches the end of the canoe. The final momentum is given by the product of the total mass and the final velocity:

Final momentum = Total mass (final) × Final velocity

Since the total mass of the system remains the same, we can substitute the initial total mass into the equation:

Final momentum = Total mass (initial) × Final velocity

Now, we need to calculate the final velocity. We can use the notion that the total initial momentum is equal to the final momentum. The initial momentum is zero, so:

Total momentum (initial) = Total momentum (final)

With this equation, we can solve for the final velocity:

Total mass (initial) × 0 = Total mass (initial) × Final velocity

0 = Final velocity

This means that the final velocity of the system is zero when the canoeist reaches the end of the canoe. Now we can substitute this value into the equation for the final momentum:

Final momentum = Total mass (initial) × 0
Final momentum = 0

Since the final momentum is zero, this implies that the mass of the canoe must be zero in order for the equation to hold. However, this is not physically possible.

Therefore, based on the given information and calculations, it seems there may be an error or missing data in the problem. Please check the given values and assumptions to ensure the correctness of the question.