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3 years ago

Please help I'll mark brainliest!!!!

Physics

2 answers:

madam [21]3 years ago

7 0

This question is based on the fundamental assumption of vector direction.

A vector is a physical quantity which has magnitude as well direction for its complete specification.

The magnitude of a physical quantity is simply a numerical number .Hence it can not be negative.

A negative vector is a vector which comes into existence when it is opposite to our assumed direction with respect to any other vector. For instance, the vector is taken positive if it is along + X axis and negative if it is along - X axis.

As per the first option it is given that a vector is negative if its magnitude is greater than 1. It is not correct as magnitude play no role in it.

The second option tells that the magnitude of the vector is less than 1. Magnitude can not be negative. So this is also wrong.

Third one tells that a vector is negative if its displacement is along north. It does not give any detail information about the negativity of a vector.

In a general sense we assume that vertically downward motion is negative and vertically upward is positive. In case of a falling object the motion is vertically downward. So the velocity of that object is negative .

So last option is partially correct as the vector can be negative depending on our choice of co-ordinate system.

exis [7]3 years ago

4 0

The velocity of a falling object is a vector that should be negative

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If you were going to build a nuclear power plant why wouldn't you build it in the middle of a desert

Tems11 [23]

You won't be able to get enough water for the reactor core cooling (you can use other methods , but more expensive) . The desert temprature is high at day, which will require additional cooling techniques to avoid over-heating the plant. Transmitting the electricity to the industrial , commercial and residual areas will cost more money, as you will need more transmission lines. Transporting the fuel to the desert will cost more at most.

Mostly this plants are established near seas.

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4 years ago

Can anybody write a short poem about friction

Luden [163]

Answer:

you will be the clouds
and I will be the sky.
you will be the ocean
and I will be the shore.
you will be the trees
and I will be the wind.

whatever we are, you and I will always collide.

There you go! Let me know if it helped.
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8 0

2 years ago

Doug, who runs track for his high school, was challenged to a race by his younger brother, matt. Matt started running first, and

eduard

The speed of Matt is 10 mph.

Doug runs 2 miles an hour faster than Matt, so let Matt’s speed equal x miles per hour. Then Doug’s speed equals x + 2 miles per hour. Each lap is one-quarter of a mile, so Doug runs 1.5 miles in the time it takes Matt to run 1.25 miles.

Rate of Matt is x

Rate of Dough is (x + 2)

Time taken by Matt is 1.25/x

Time taken by Dough is 1.25/(x + 2)

Distance covered by Matt is 1.25

Distance covered by Dough is 1.5

Dough and Matt took the same amount of time from the time Doug started, so make an equation by setting the two times in the chart equal to each other, and then solve for x:

$\frac{1.5}{(x + 2)}$ = $\frac{1.25}{x}$

1.5x = 1.25(x + 2)

1.5x = 1.25x + 2.5

0.25x = 2.5

x = 10

So Matt ran at 10 miles per hour.

To know more about time, speed and distance, visit: brainly.com/question/26046491

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7 0

1 year ago

A student needs to conduct a reaction that combines chemicals A and B to synthesize product AB . If we write this as a chemical

rusak2 [61]

Answer : The number of molecules of A needed to make 5000 molecules of AB will be, 5000

Explanation :

Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

The given balanced chemical reaction is,

$A+B\rightarrow AB$

As per question, molecule B is an excess reagent because it had enough molecule to make 5000 molecules of AB. So, molecule A is limiting reagent.

From the balanced reaction, we conclude that

As, 1 molecule of AB produced from 1 molecule of A

So, 5000 molecule of AB produced from 5000 molecule of A

Hence, the number of molecules of A needed to make 5000 molecules of AB will be, 5000

8 0

3 years ago

The figure above shows the net force exerted on an object as a function of the position of the object. The object starts from re

weqwewe [10]

Answer:

0.06 Kg

Explanation:

From the question given above, the following data were obtained:

Initial velocity (u) = 0 m/s

Final velocity (v) = 3.0 m/s

Distance (s) = 0.09 m

Net Force (F) = 3 N

Mass (m) =?

Next, we shall determine the acceleration of the object. This can be obtained as follow:

Initial velocity (u) = 0 m/s

Final velocity (v) = 3.0 m/s

Distance (s) = 0.09 m

Acceleration (a) =?

v² = u² + 2as

3² = 0² + (2 × a × 0.09)

9 = 0 + 0.18a

9 = 0.18a

Divide both side by 0.18

a = 9 / 0.18

a = 50 m/s²

Finally, we shall determine the mass of the object. This can be obtained as follow:

Net Force (F) = 3 N

Acceleration (a) = 50 N

Mass (m) =?

F = ma

3 = m × 50

Divide both side by 50

m = 3 / 50

m = 0.06 Kg

Therefore, the mass of the object is 0.06 Kg

5 0

3 years ago