Question

Two friends, Burt and Ernie, are standing at opposite ends of a uniform log that is floating in a lake. The log is 4.0 m long and has mass 200 kg. Burt has mass Relative to the shore, what distance has the log moved by the time Ernie reaches Burt?

Answer 1

The log does not move relative to the shore by the time Ernie reaches Burt.

Step-by-step explanation:

To find the distance the log has moved when Ernie reaches Burt, we can consider the principle of conservation of momentum. Since the log and Ernie are initially at rest, the total momentum of the system is zero. When Ernie reaches Burt, the log will start moving in the opposite direction with a certain velocity. We can use the equation:

mass of log * velocity of log = mass of Ernie * velocity of Ernie

Let's assume the velocity of the log is v and the velocity of Ernie is 0. Since both Burt and Ernie have mass, we need to consider both of their masses:

200 kg * v = mass of Ernie * 0

Since mass of Ernie * 0 = 0, we can conclude that the velocity of the log is also 0. This means that the log does not move relative to the shore by the time Ernie reaches Burt.