Chemistry, 03.03.2020 10:20 camila68

8. If the velocity of an object changes from 15 m/s to 50 m/s during a time interval
of 4 s, what is the acceleration of the object?
9. If the acceleration in question 8 is constant, what's the average velocity of the
object described?

Answers: 3

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Answers

Answer from: Jana1517

Acceleration of the object is 8.75 m/s² and average velocity is 32.5 m/s

Explanation:

Given initial velocity = 15 m/s and final velocity = 50 m/s and time = 4s

Acceleration of the object = Change in velocity/Time

= 50 - 15/4 = 35/4 = 8.75 m/s²

Average velocity = initial velocity + final velocity/2

= 15 + 50/2 = 65/2 = 32.5 m/s

Answer from: Quest

That result from subduction of oceanic plates beneath lighter continental plates. most of the earth's volcanoes are located around the pacific ring of fire because that the location of most of the earth's subduction zones.

Answer from: Quest

assuming that your periodic table has eighteen columns, you should highlight the four elements in the third column from the left of the table.

explanation

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the $3d$ have energy higher than those in the $4 s$ orbital while lower than those of the $4 p$ orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the $4s$ orbital is therefore filled right after $3p$ orbitals and before $3 d$ orbitals.

potassium has electron configuration $[\text{ar}] 4 s^{1}$ and calcium $[\text{ar}] 4 s^{2}$ . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration $[\text{ar}] 4 s^{2} \; 3d^{1}$ and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the $ns^{2} \; (n-1) p^{1}$ and should be highlighted as well.