a substance dissolves.
like adding a soluble salt to water, it just dissolves, i.e dissociates homogeneously as water is able to dissociate salts (ionic compounds) into its ions. (it can also dissociate other non-ionic compounds like HCL)
the salt still remains chemically as a salt and is unchanged chemically thus it is not an indication of a chemical reaction as no chemical reaction has taken place.
the formation of a precipitate is a chemical reaction because a new substance (i.e new chemical) is formed. For example adding aqueous sodium hydroxide into an aqueous solution with CU2+ cations will form a blue precipitate (that is copper (II) hydroxide which is insoluble, hence it precipitates). Since a new chemical is formed, a chemical reaction has taken place and thus indicates a chemical reaction.
color change... im not sure but usually a color change will only occur when a new substance is formed. Like iron corrodes (i.e rust) slowly in moist air to form hydrated iron (III) oxide that is rust. (brown color).
usually adding a mixture to a mixture has little energy change, i.e little heat taken in by the reaction mixture or little heat given out by the reaction mixture. Whereas when a new substance is formed, there is usually noticeable energy change like the container gets colder or hotter (without heat being supplied of course). For example dissolving basic oxides into water releases energy ( more energy released than gained = exothermic reaction).
i think that should be the answer... hope it helped :D
Answer: momentum = 6kgm/s
Explanation:
given that the baseball pitcher is at stationary position, his velocity will be equal to zero. If velocity is zero, his linear momentum will therefore equal to zero.
Linear momentum is the product of mass and velocity. Given that the baseball has
Mass M = 0.15 kg
Velocity V = 40 m/s
Momentum = MV
Momentum = 0.15 × 40 = 6 kgm/s
The Answer is TRUE. Hope it helps
Answer:
Centripetal acceleration,

Explanation:
Centripetal acceleration:
Centripetal acceleration is the idea that any object moving in a circle, in something called circular motion, will have an acceleration vector pointed towards the center of that circle.
Centripetal means towards the center.
Examples of centripetal acceleration (acceleration pointing towards the center of rotation) include such situations as cars moving on the cicular part of the road.
An acceleration is a change in velocity.
Formula for Centripetal acceleration:

Given here,
Velocity = 4.5 m/s
radius = 7.7 m
To Find :

Solution:
We have,

Substituting given value in it we get

Centripetal acceleration,
