Changes in state of matter would be a physical change to whatever it is that you are changing so I think it would be B.Molecules because in order for something to change the molecules have to be moving apart from one another but I maybe wrong depending on what it is your looking at
Answer:
(D) 42.4N
Explanation:
Since the frame is at rest, the net force acting on it must be 0. There are three forces acting on it: the gravity and the opposing forces of the two cables.
Since the gravity is a vertical force, we are only interested in the vertical components of the remaining forces. The net force equation is
F_net = 0 = F_g -2 * F_y
The vertical force of one cable (using the information in the drawing) is:
F_y = 30N * sin 45 deg = 21.21N
Now the weight can be determined:
0 = F_g - 2 * F_y
F_g= 2 * F_y = 2 * 21.21N = 42.4N
The weight of the frame is about 42.4N.
<u>Answer:</u>
Mass of combined products = 20.4 grams
Mass of combined product and Erlenmeyer flask = 136 grams
<u>Explanation:</u>
By law of mass conservation, mass cannot be destroyed or created. So mass before reaction is mass after reaction.
Mass of lead(II) nitrate = 15.6 grams
Mass of potassium iodide = 4.8 grams
Mass of the Erlenmeyer flask = 115.6 grams
Mass of reactants = 15.6 + 4.8 = 20.4 grams
So mass of products = 20.4 grams
Mass of combined product and Erlenmeyer flask = 115.6 + 20.4 = 136 grams