Answer:
Tha ball- earth/floor system.
Explanation:
The force acting on the ball is the force of gravity when ignoring air resistance. At the moment the player releases the ball, until it reaches the top of its bounce, the small system for which the momentum is conserved is the ball- floor system. The balls exerts and equal and opposite force on the floor. <u>Here the ball hits the floor, because in any collision the momentum is conserved. Moment of the ball -floor system is conserved</u>. Mutual gravitation bring the ball and floor together in one system. As the ball moves downwards, the earth moves upwards, although with an acceleration on the order of 1025 times smaller than that of the ball. The two objects meet, rebound and separate.
<span>D. sugar changes from white to a light amber color
We're looking for a chemical change. So let's examine the options and see what happening with them.
A. adding cream and milk to the mixture
She's just making a mixture here. No unexpected reactions or changes happen as she adds the cream and milk. So this is the wrong answer.
B. mixing the sugar with water
Dissolving the sugar in water. Once again, nothing unusual happens and if she were to evaporate the water, she'd be left with the original sugar. So this is the wrong answer.
C. melting the sugar
Just starting a simple phase change. Once again, no the right answer.
D. sugar changes from white to a light amber color
She's melted the sugar and has a clear fluid. As she continued to heat this fluid, it suddenly turns light amber. She has made a permanent change to the substance that she can't undo by simply physical means. She has converted part of the sugar into caramel. So a chemical change has happened here.</span>
A I think because sublimation is when something skips melting and goes directly to vapor
