Alexis is studying how lenses work. She looks through a

A horizontal line on a distance-time graph means the object is

IgorLugansk [536]

At rest because if the distance is not changing, then it is not moving any further, so it must not be moving! The time keeps going no matter what, so the distance, whether it is 0 m or 10,000 km, if the y is horizontal the distance does not change.

6 0

4 years ago

C.<br>Difference between<br>D) solar energy and fossil fuel energy

jonny [76]

hii

here's your answer

Fossil fuel use is integrated into the fabric of American society. Natural gas, petroleum and coal together accounted for more than 80 percent of energy use in the United States in 2012. Meanwhile, more than 5 gigawatts of solar power capacity was scheduled to come online in 2013 -- about as much capacity as was added for coal plants over a nearly 20-year span. The characteristics of solar power and fossil fuels drive the desire to adopt a particular energy source for a specific application, and they also limit the possible applications of a specific energy source.

HOPE IT HELPS YOU OUT PLEASE MARK IT AS BRAINLIEST AND FOLLOW ME PROMISE YOU TO FOLLOW BACK ON BRAINLY.IN

6 0

3 years ago

as you take a short canoe trip on the Brazos River you paddle your canoe 200 miles up the river in 420 seconds and then turn aro

Maurinko [17]

200 miles/420 secs = 10/21
350 mile/280 secs = 5/4

(5/4+10/21)/2= 145/168 miles per sec
or .86 miles/sec

8 0

3 years ago

Uniform, identical bricks 20 cm long are stacked so that 4 cm of each brick extends beyond the brick beneath. How many bricks ca

Butoxors [25]

Answer:

6 bricks

Explanation:

For the bricks system to NOT fall over, then the center of mass of the system must lie within the touching area of the bottom brick.

Let the reference line be at the left end of the base brick, and the bricks are being stacking to the right direction.

- The 1st brick would have a center of mass at 20/2 = 10 cm or 10 + 0, this is < 20 cm so it stays

- 2 stacked bricks would have a center of mass at (10 + 14)/2 = 12 cm or 10 + 2, this is also < 20 cm so it stays

- 3 stacked bricks would have a center of mass at (10 + 14 + 18) / 3 = 14 cm or 10 + 2*2, this is also < 20 cm so it stays

- 4 stacked bricks would have a center of mass at (10 + 14 + 18 + 22)/4 = 16 cm or 10 + 2*3, this is also < 20 cm so it stays

- 5 stacked bricks would have a center of mass at (10 + 14 + 18 + 22 + 26)/5 = 18 cm or 10 + 2*4, this is also < 20 cm so it stays

- 6 stacked bricks would have a center of mass at (10 + 14 + 18 + 22 + 26 + 28)/5 = 20 cm or 10 + 2*5, this is also <= 20 cm so it stays before tipping over.

- The 7th brick would make everything fall down.

4 0

4 years ago

A scientist fixes a test charge q′ to point P and then measures the electrostatic force it experiences there. She then calculate

nordsb [41]

Answer:

<em>Correct answer: B.</em>

Explanation:

Electrostatic Field

It measures the electric effect of a charge distribution in its surroundings. If we wanted to test or measure the electric field by using a point-charge of value q', then the electric field is

$\displaystyle E=\frac{F}{q'}$

The electrostatic force between two point charges is

$\displaystyle F=\frac{k\ q_1\ q'}{r^2}$

So, the electric field is

$\displaystyle E=\frac{\frac{k\ q_1\ q'}{r^2}}{q'}$

$\displaystyle E=\frac{k\ q_1}{r^2}$

The theory shows that the electric field doesn't depend on the test charge used, i.e., if we now use q'=-q', the electric force will be of the same magnitude but in the opposite direction, thus the electric field will be the same. Let's recall the formula is used to compute the scalar value of the field, the direction must be studied separately.

Now, if we changed the test charge to another value, say 2q, the measured force will be

$\displaystyle F=\frac{k\ q_1\ 2q}{r^2}$

And the new electric field is

$\displaystyle E=\frac{k\ q_1}{r^2}$

We can see the electric field is not affected by the value of the test charge.

Finally, if we move the test charge to another location and keep the same charge, the electric force will vary and the electric field will be different.

Correct answer: B.

7 0

3 years ago