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3 years ago

I think I know this one but I don’t at the same time

Physics

1 answer:

galben [10]3 years ago

8 0

Answer: B.) 6

Explanation:

To answer this problem you get the number of students who attended Wednesday (18) and the number of students who attended Tuesday (12) and subtract 18 - 12 = 6

Answer = B.) 6

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Read the scenario. A car travels 25 m/s forward for 10 s. Which option accurately identifies the measurements within the scenari

Phantasy [73]

Explanation:

It is given that,

A car travels 25 m/s forward for 10 s.

Solution,

For a vector, a quantity must have both magnitude as well as the direction. For a scalar, a quantity have only the magnitude. In this case, the car moves in forward direction. This is the only difference between the vector and the scalar.

Out of given option,s the correct option is (c) "The measurement 25 m/s is the only vector quantity because it is a measurement of speed".

5 0

3 years ago

A race car travels 40 m/s around a banked (45° with the horizontal) circular (radius = 0.20 km) track. What is the magnitude of

OLEGan [10]

Answer:

c) $F_{net} = 0.640 kN$

Explanation:

As we know that resultant force is the net force that is acting on the system

As per Newton's II law we know that net force is product of mass and acceleration

so we will have

$F_{net} = ma$

here we know

m = 80 kg

for circular motion acceleration is given as

$a_c = \frac{v^2}{R}$

$a_c = \frac{40^2}{200} = 8 m/s^2$

now we have

$F_{net} = 80 \times 8$

$F_{net} = 640 N$

$F_{net} = 0.640 kN$

7 0

3 years ago

Sandi believes that people who eat at McDonald's are overweight, so she decides to do a naturalistic observation of people who e

lubasha [3.4K]

Answer:

observer bias

Explanation:

Based on the information provided within the question the thing that should concern us the most about Sandi's observations is Observer Bias. This term refers to the tendency of a researcher to see what they want as opposed to what is actually happening. This can be said because of Sandi's belief that McDonald clients are all overweight, by having this belief before actually having come to this conclusion with a series of tests, it might lead her to believe this to be true regardless of what she observes during the experiment.

I hope this answered your question. If you have any more questions feel free to ask away at Brainly.

6 0

3 years ago

Which type of matter is gold an element used in making jewelry A.) A heterogeneous mixture B.) A pure substance C.) A crystallin

Mnenie [13.5K]

Answer:

Explanation:

<em>The gold used in the making of jewelry is usually not pure but a heterogeneous mixture of metals. Pure gold is quite soft and even though it may look better in appearance compared to those made using heterogeneous mixtures, it usually bends easily. Hence, in order to make the jewelry more durable, gold is usually mixed with other metals to form a heterogeneous mixture. </em>

The correct option is A.

7 0

3 years ago

Read 2 more answers

Lasers are now used in eye surgery. Given the wavelength of a certain laser is 514 nm and the power of the laser is 1.1 W, how m

Leno4ka [110]

Answer: $1.593*10^{17} photons$ released if the laser is used 0.056 s during the surgery

Explanation:

First, you have to calculate the energy of each photon according to Einstein's theoty, given by:

$E =\frac{hc}{\lambda}$

Where $\lambda$ is the wavelength, $h$ is the Planck's constant and $h$ is the speed of light

$h = 6.626*10^{-34} \frac{m^{2} kg }{s}$ -> Planck's constant

$c = 3*10^{8} \frac{m}{s}$ -> Speed of light

So, replacing in the equation:

$E =\frac{ 6.626*10^{-34} \frac{m^{2} kg }{s}*3*10^{8} \frac{m}{s}}{514*10^-9 m}$

Then, the energy of each released photon by the laser is:

$E = 3.867*10^{-19} \frac{J}{photons}$

After, you do the inverse of the energy per phothon and as a result, you will have the number of photons in a Joule of energy:

$\frac{1}{3.867*10^{-19}} = 2.586*10^{18} \frac{photons}{J}$

The power of the laser is 1.1 W, or 1.1 J/s, that means that you can calculate how many photons the laser realease every second:

$2.586*10^{18}\frac{photons}{J} * 1.1 \frac{J}{s} = 2.844*10^{18} \frac{photons}{s}$

And by doing a simple rule of three, if $2.844*10^{18} photons$ are released every second, then in 0.056 s:

$0.056 s*2.844*10^{18} \frac{photons}{s} = 1.593*10^{17} photons$ are released during the surgery

5 0

3 years ago