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3 years ago

Which describes how chemical changes are different from physical changes?

Physics

1 answer:

lions [1.4K]3 years ago

6 0

Answer:

B. Chemical changes involve the formation of a new substance.

Explanation:

They can both release energy, both can be measured, and chemical changes can be caused by oxygen, so I believe it would be B.

You might be interested in

What is the momentum of a vehicle that has a mass of 800 kg and is moving at a velocity of 5 m/s

yarga [219]

Answer:

4000 kg.m/s

Explanation:

p=mv

m=800 kg

v=5 m/s

p=(800)(5)= 4000 kg.m/s

3 0

3 years ago

You are measuring the volume of a chemical beaker how would u take the measurment?

8090 [49]

I think its d because lifting it would make the chemical swish around and that will make it so you cant get the right measurement. hope this helps :)

6 0

2 years ago

Match the indices of refraction with the corresponding effects on the waves.

Yanka [14]

Answer:

B) waves speed up

C) waves bend away from the normal

Explanation:

The index of refraction of a material is the ratio between the speed of light in a vacuum and the speed of light in that medium:

$n=\frac{c}{v}$

where

c is the speed of light in a vacuum

v is the speed of light in the medium

We can re-arrange this equation as:

$v=\frac{c}{n}$

So from this we already see that if the index of refraction is lower, the speed of light in the medium will be higher, so one correct option is

B) waves speed up

Moreover, when light enters a medium bends according to Snell's Law:

$n_1 sin \theta_1 = n_2 sin \theta_2$

where

$n_1 ,n_2$ are the index of refraction of the 1st and 2nd medium

$\theta_1,\theta_2$ are the angles made by the incident ray and refracted ray with the normal to the interface

We can rewrite the equation as

$sin \theta_2 = \frac{n_1}{n_2}sin \theta_1$

So we see that if the index of refraction of the second medium is lower ( $n_2$ ), then the ratio $\frac{n_1}{n_2}$ is larger than 1, so the angle of refraction is larger than the angle of incidence:

$\theta_2>\theta_1$

This means that the wave will bend away from the normal. So the other correct option is

C) waves bend away from the normal

3 0

3 years ago

A baseball bat changes the momentum of a ball with an impulse of 13.8 Nᐧs. What is the average force that the bat exerts on the

vladimir2022 [97]

Answer:

13800 N

Explanation:

Impulse is the product of average force and time expressed as I=Ft where I is the impulse which results into change in momentum, F is the average force and t is the time of impact. Making F the subject of formula then

$F=\frac {I}{t}$