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2 years ago

The black board appears black because:

Physics

1 answer:

marishachu [46]2 years ago

8 0

Answer:

I think its C All visible light wavelengths (ROYGBV) are absorbed by the board

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you (60 kg) are standing in a (500 kg) elevator that is moving upwards from a ground floor on a building what is the power ratin

PtichkaEL [24]

Explanation:

Power = work / time

Power = force × distance / time

P = (650 kg) (10 m/s²) (20 m) / (15 s)

P = 8667 W

5 0

3 years ago

What would happen to a ray of light when it enters: - a) glass to water b) water to air?

hammer [34]

Answer:

<em>The answer is B) water to air</em>

7 0

2 years ago

What is endurance? a). the ability to run faster b). a combination of balance and coordination c). how much you can stretch d).

Alex787 [66]

Answer:

D. the ability to exercise for longer periods of time

Explanation:

For example, when someone does endurance training, they are stretching their body's ability to do a certain exercise for longer times as opposed to increasing strength.

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3 years ago

An electron is released from rest in a weak electric field given by E =-2.30 x 10-10 N/Cj. After the electron has traveled a ver

Goshia [24]

Explanation:

It is given that,

An electron is released from rest in a weak electric field of, $E=2.3\times 10^{-10}\ N/C$

Vertical distance covered, $s=1\ \mu m=10^{-6}\ m$

We need to find the speed of the electron. Let its speed is v. Using third equation of motion as :

$v^2-u^2=2as$

$v^2=2as$ .............(1)

Electric force is $F_e$ and force of gravity is $F_g$ . As both forces are acting in downward direction. So, total force is:

$F=mg+qE$

$F=9.1\times 10^{-31}\times 9.8+1.6\times 10^{-19}\times 2.3\times 10^{-10}$

$F=4.57\times 10^{-29}\ N$

Acceleration of the electron, $a=\dfrac{F}{m}$

$a=\dfrac{4.57\times 10^{-29}\ N}{9.1\times 10^{-31}\ kg}$

$a=50.21\ m/s^2$

Put the value of a in equation (1) as :

$v=\sqrt{2as}$

$v=\sqrt{2\times 50.21\times 10^{-6}}$

v = 0.010 m/s

So, the speed of the electron is 0.010 m/s. Hence, this is the required solution.

6 0

3 years ago

When an unbalanced force acts on an object the change in the objects ____or ____ depends on the size and direction of the force

timama [110]

When an unbalanced force acts on an object the change in the object state of rest or motion depends on the size and direction of the force.

If a body is at state of rest or motion, when an unbalanced external force acts on it, its starts moving in the direction of force and magnitude of its velocity or acceleration depends on the magnitude of force applied.

7 0

3 years ago

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