C . Record the time to complete a chemical reaction
<span>We see only one side of the moon from earth because the moons period of rotation and revolution are equal. The moon rotates around the Earth at the exact speed as it rotates around its won axis (revolution). The result is: the same side of the moon is facing the Earth. If the moon doesn't rotate on it's axis we on the Earth would see all of the sides of the Moon.</span>
21) Acceleration from D to E: ![1 m/s^2](https://tex.z-dn.net/?f=1%20m%2Fs%5E2)
22) The acceleration of the bus from D to E is ![1 m/s^2](https://tex.z-dn.net/?f=1%20m%2Fs%5E2)
Explanation:
21)
The acceleration of an object is equal to the rate of change of velocity of the object. Mathematically:
![a=\frac{v-u}{t}](https://tex.z-dn.net/?f=a%3D%5Cfrac%7Bv-u%7D%7Bt%7D)
where
u is the initial velocity
v is the final velocity
t is the time elapsed
In this problem, we want to measure the acceleration of the bus from point D to point E. We have:
- Initial velocity at point D: u = 0
- Final velocity at point E: v = 5 m/s
- Time elapsed from D to E: t = 21 - 16 = 5 s
Therefore, the acceleration between D and E is
![a=\frac{5-0}{5}=1 m/s^2](https://tex.z-dn.net/?f=a%3D%5Cfrac%7B5-0%7D%7B5%7D%3D1%20m%2Fs%5E2)
22) This question is the same as 21), so the result is the same.
Learn more about acceleration:
brainly.com/question/9527152
brainly.com/question/11181826
brainly.com/question/2506873
brainly.com/question/2562700
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It can be described as <span>a pure substance and an element. </span>
Answer:
B) the change in momentum
Explanation:
Impulse is defined as the product between the force exerted on an object (F) and the contact time (
)
![I=F \Delta t](https://tex.z-dn.net/?f=I%3DF%20%5CDelta%20t)
Using Newton's second law (F = ma), we can rewrite the force as product of mass (m) and acceleration (a):
![I=(ma) \Delta t](https://tex.z-dn.net/?f=I%3D%28ma%29%20%5CDelta%20t)
However, the acceleration is the ratio between the change in velocity (
) and the contact time (
):
, so the previous equation becomes
![I=m \frac{\Delta v}{\Delta t}\Delta t](https://tex.z-dn.net/?f=I%3Dm%20%5Cfrac%7B%5CDelta%20v%7D%7B%5CDelta%20t%7D%5CDelta%20t)
And by simplifying
,
![I=m \Delta v](https://tex.z-dn.net/?f=I%3Dm%20%5CDelta%20v)
which corresponds to the change in momentum of the object.