Because the top layer of a pool will be warmer than the bottom layer, that why filtration is important to cycle the water evenly.
The answer is D. Either absorbed or reflected. The reason is because if no light is being shown on the other side, the substance is not letting any light pass through. Since we do not know anything else about the substance, we do not know which one of the two it is doing. The scientist would not see any light on the detector if 100% of the light is reflected and the same thing would happen if 100% of the light was absorbed.
Answer: Zero.
Explanation:
By the first Newton's law, we know that:
every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.
Now, we know that the car is moving with constant speed, then there is no net force acting on the car, which means that the car is already in equilibrium.
Then if we add one force to the situation, the car will not be anymore in equilibrium.
The correct option is zero.
When the property of the medium changes.
For this case it is necessary to consider the assessments made between collisions of 'immovable' objects. In this case the earth is the immovable object or at least, it is approached by its mass. Considering the case of an inflatable ball of mass m that travels at a speed v towards the ground, it hits the floor and bounces with speed -v (Negative). The earth does not move, however, the momentum of the ball has changed by 2mv since the speed went from positive to negative. Applying the conservation of the momentum we know that the change of the momentum on the fly would be given under the function

Considering the direction of the velocities this expression can be rewritten as


Therefore the correct answer would be
C. Only the momentum of the ball is changed by the collision