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3 years ago

We only see objects because they absorb light. True or False?

Physics

1 answer:

Alenkasestr [34]3 years ago

3 0

Answer:

true

Explanation:

i think it's true because I took a quiz on this

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Electromagnetic waves can transfer energy without a(n) _____________ (medium/electric field).

KATRIN_1 [288]

Medium.
Medium is matter, and electromagnetic waves do not need matter to travel. Just like the sun, its plasma light travels across space to reach us.

7 0

3 years ago

How many atoms are in a sample of 1.83 moles of potassium (K) atoms?

telo118 [61]

<span>Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles.

</span>1.83 moles K (6.022 x 10^23 atoms / mole ) = 1.10 x 10^24 atoms K

4 0

3 years ago

What is the speed of an electron that has been accelerated from rest through a potential difference of 1020 V?

sashaice [31]

<span>a. KE in electron volts is 1020 eV.
b. KE in Joules is e(1020) = (1.6022E-19)(1020) = 1.634E-16
c. KE = (1/2)mv^2, so v = sqrt[2*KE/m] = 18.94E6 m/s

note: m is the mass of an electron = 9.109e-31 kg

I hope my answer has come to your help. Thank you for posting your question here in Brainly.
</span>

8 0

3 years ago

A girl and a boy are riding on a merry go round that is turning at a constant rate. The girl is near the outer edge, and the boy

galina1969 [7]

Answer:

The girl has greater tangential acceleration

Explanation:

The angular acceleration ( $\alpha$ ) of the merry go round is equal to the rate of the change of the angular velocity, $\omega$ :

$\alpha = \frac{d\omega}{dt}$

Since all the points of the merry go round complete 1 circle in the same time, the angular velocity of each point of the merry go round is the same, and so all the points also have the same angular acceleration.

The tangential acceleration instead is given by

$a_t = \alpha r$

where

$\alpha$ is the angular acceleration

r is the distance from the centre of the merry go round

Since the girl is near the outer edge and the boy is closer to the centre, the value of r for the girl is larger than for the boy, so the girl has greater tangential acceleration.

5 0

3 years ago

An electron is accelerated within a particle accelerator using a 100 MV electric potential. The 100 MeV electron moves along an

Delicious77 [7]

Answer:

The length of the tube is 3.92 m.

Explanation:

Given that,

Electric potential = 100 MV

Length = 4 m

Energy = 100 MeV

We need to calculate the value of $\gamma$