Alex threw a stick in a river and watched as the river carried it away. He scooped a pail of water from the river and noticed that a leaf was floating in the pail without moving on the surface of the water. Why did the stick move in the river and the leaf stay still in the pail if it was all the same water?

A.The river water cooled off and lost energy when Alex scooped it up into the pail.
B.There is more water in the river than in the pail so the river could move the stick.
C.The water in the river has enough energy to move the stick since it is flowing downhill.
D.Wind could push the stick on the river but could not get to the leaf protected in the pail.

What do you think?

In this scenario, we have a stick that moves in the river while a leaf stays still in the pail despite both being in the same water. Let's analyze the answer options to understand why this happens.

A. The river water cooled off and lost energy when Alex scooped it up into the pail.
This answer option suggests that the water in the pail lost energy when it was scooped up, which would explain why the leaf stayed still. However, it does not explain why the stick moved in the river. Therefore, this option does not fully explain the situation.

B. There is more water in the river than in the pail so the river could move the stick.
This answer option suggests that the stick moved in the river because there is more water in the river than in the pail. While this is true, it does not explain why the leaf stayed still in the pail. Therefore, this option does not fully explain the situation.

C. The water in the river has enough energy to move the stick since it is flowing downhill.
This answer option suggests that the water in the river has enough energy to move the stick because it is flowing downhill. This explanation is correct as the flowing water in the river creates a current that can carry objects like the stick downstream. However, it does not explain why the leaf stayed still in the pail.

D. Wind could push the stick on the river but could not get to the leaf protected in the pail.
This answer option suggests that the stick moved in the river because wind could push it along the surface of the water. However, it correctly points out that the wind cannot reach the leaf in the pail, explaining why it stays still. This answer option explains both the movement of the stick in the river and the stillness of the leaf in the pail, making it the most accurate explanation in this scenario.

Therefore, the correct answer is D. Wind could push the stick on the river but could not get to the leaf protected in the pail.