Answer:
Explanation:
Electron's kinetic energy = 2 eV
= 2 x 1.6 x 10⁻¹⁹ J
1/2 m v² = 3.2 x 10⁻¹⁹
1/2 x 9.1 x 10⁻³¹ x v² = 3.2 x 10⁻¹⁹
v² = .703 x 10¹²
v = .8385 x 10⁶ m/s
Electrons revolve in a circular orbit when forced to travel in a magnetic field whose radius can be expressed as follows
r = mv / Bq
where m , v and q are mass , velocity and charge of electron .
here given magnetic field B = 90 mT
= 90 x 10⁻³ T
Putting these values in the expression above
r = mv / Bq
= 
= .052 mm.
Answer:
<h2>B) Newton's 2nd law</h2>
Explanation:
<h2>From; force= mass × acceleration </h2><h2> f= m×a </h2><h2>where a(acceleration)= velocity/time</h2><h3> force = mv/t</h3><h3>But momentum(p) = Mass × velocity </h3><h2>hence force =p/t </h2><h3>that is Momentum = force × time ( Newton's 2nd law)</h3>
Normal force is mass x gravity, so mass x 9.81
For the answer to the question above asking to d<span>etermine the density of the proton.
</span>Density is mass over volume.
The volume of a sphere is 4πr³/3. r is half the diameter.
So the density would be 2.3×10¹⁷ kg/m³.
I hope my answer helped you. Feel free to ask more questions. Have a nice day!
Answer: The correct option is option E (the Sun is seen blocking different constellations in the course of a year.
Explanation:
The earth, which is one of the planets of the solar system that supports life, is shperical in shape. The spherical ( round) shape of the earth is marked by the intervening highlands and oceans on its surface.
Evidence to show that the earth is shperical are:
--> The Lunar eclipse: During an eclipse of the Moon, the shadow of the Earth is always seen to be round.
--> Ships Visibility: When ships travel a large distance away, we see their hulls disappear first and their masts disappear last.
-->Altitude of Polaris (North Star): The height of the North Star changes as we travel to different latitudes. That is ,increases as you move toward the North pole, or decreases as you move toward the equator.
--> Aerial photographs: Photographs of the Earth from space always show a round body.
The statement that doesn't prove that the earth is spherical in shape is (the Sun is seen blocking different constellations in the course of a year). The sun is seen in front of stars blocking different constellation in a year because the earth orbits round the sun in a year and not that it is shperical in shape.
