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3 years ago

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After a while, the car started to go around a long bend, still maintaining its constant speed of 55 miles per hour. Is there a n

et (unbalanced) force acting on the car? 1. No; the speed of the car does not change. 2. Cannot be determined 3. No; the velocity of the car does not change. 4. Yes; its direction is not the same as the velocity. 5. Yes; its direction is the same as the velocity.

1 answer:

sukhopar [10]3 years ago

6 0

Answer:

4) True. The change of direction needs an unbalanced force

Explanation:

Let us propose the resolution of the problem using Newton's second law.

F = m a

As the car is spinning the acceleration is centripetal

a = v2.r

F = m v2 / r

We can see that as the velocity of a vector even if its module does not change, the change of direction requires an external force.

Now we can analyze the statement if they are true or false

1) and 3) False, even when the speed changes, the direction changes

2) False with the speed change can be determined

4) True. The change of direction needs an unbalanced force

5) False are different things. the direction is where it is going and the speed is the magnitude of the vector

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3 years ago

A tow truck exerts a force of 3000 n on a car, accelerating it at 2 meters per second per second. what is the mass of the car?

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3 years ago

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3 years ago

The periodic table is an arrangment of the chemical elements, ordered by atomic number, into families, and by doing so illustrat

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Answer:

<em><u>Option B) reactive to nonreactive</u></em>

Explanation:

<u>A) Solid to gas</u>

This might apply, because most of the gases are to the right portion of the periodic table

There are just a few elements that are gases at room temperature; a total of 11: six noble gases (group 18), two halogens (group 17), oxygen (group 16), nitrogen (group 15), and hydrogen (group 1).

Hydrogen is an exception to this trend because they are in the left part of the periodic table.

<u>B) Reactive to nonreactive</u>

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Hence, this is the one that cannot apply.

<u>C) Metal to metalloid to nonmetal</u>

It is true that the metallic character of the elements decreases from left to right; the metals are to the left, going to the right you find some metalloids, and further to the right you find the nonmetals.

Hence, this trend is correct.

<u />

<u>D) Increasing number of outer-shell electrons</u>

The number of outer-shell electrons definetly increase from left to right.

The number of electrons in neutral atoms equals the number of protons (to balance the positive and negative charges). Since, the atomic number (the number of protons) increase from left to right, the number of electrons also increase.

In a period (a row of the periodic table) the electrons add to the same outer-shell, then you will find that the number of electrons of the outer-shell increase from left to right. Hence, this is also a correct trend.

In conclusion, the only trend that does not apply is the described by the option B).

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3 years ago

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