30grams
Explanation:
If a reaction starts with 30grams then the reaction should end with 30grams.
This in conformity with the law of conservation of mass.
- The law states that "in an isolated system, mass is neither created nor destroyed during chemical transformation".
- Mass is the quantity of matter contained in a substance.
- In chemical reactions, the mass of reactants must always be the same with the mass of the product baring any loss.
- In an isolated system, there is no exchange of energy and mass.
- Chemical systems are usually treated as isolated systems in which mass is conserved.
Learn more:
Chemical laws brainly.com/question/5896850
#learnwithBrainly
Friction can be bad by being too strong or too weak.
<span>Sometimes, when it is too strong, it decreases efficiency since some energy is wasted and turns to heat. Friction can also d</span><span>amage equipment/objects like when you slide it on the floor.
</span>
When friction is too weak, like for instance when there is black ice- our center of gravity is displaced too quickly and we can fall. Likewise, if there is a lot of slush on the ground, cars can slip and slide.
Answer:
nitrogen
Explanation:
because I also had this in exam and I was correct
Answer:
v ’= 21.44 m / s
Explanation:
This is a doppler effect exercise that changes the frequency of the sound due to the relative movement of the source and the observer, the expression that describes the phenomenon for body approaching s
f ’= f (v + v₀) / (v-
)
where it goes is the speed of sound 343 m / s, v_{s} the speed of the source v or the speed of the observer
in this exercise both the source and the observer are moving, we will assume that both have the same speed,
v₀ = v_{s} = v ’
we substitute
f ’= f (v + v’) / (v - v ’)
f ’/ f (v-v’) = v + v ’
v (f ’/ f -1) = v’ (1 + f ’/ f)
v ’= (f’ / f-1) / (1 + f ’/ f) v
v ’= (f’-f) / (f + f’) v
let's calculate
v ’= (3400 -3000) / (3000 +3400) 343
v ’= 400/6400 343
v ’= 21.44 m / s
Answer:
Ultraviolet wave
Explanation:
Ultraviolet waves would be best used to sterilize a surface expose to bacteria because it will completely destroy them.
Most medical equipment are usually sanitized by using this rays because the DNA of most bacteria can be innervated upon exposure to these ray.
Ultraviolet rays are energetic and more powerful than the normal visible light and subsequent long wavelength radiations.
Generally, ultraviolet rays is a very harmful electromagnetic radiation.
