Answer:
:Electric charge is a basic property of electrons, protons and other subatomic particles. Electrons are negatively charged while protons are positively charged. ... Things that have the same charge push each other away (they repel each other). This is called the Law of Charges.
Explanation:
Answer:

Explanation:
Given:
- angle of launch of projectile from horizontal,

- range of projectile,

<u>We have formula for the range of projectile:</u>

putting the respective values

is the velocity with which Tom should jump to land on the other roof.
Here's the part you need to know:
(Weight of anything) =
(the thing's mass)
times
(acceleration of gravity in the place where the thing is) .
Weight = (mass ) x (gravity) .
That's always true everywhere.
You should memorize it.
For the astronaut on Saturn . . .
Weight = (mass ) x (gravity) .
Weight = (68 kg) x (10.44 m/s²)
= 709.92 newtons .
__________________________________
On Earth, gravity is only 9.8 m/s².
So as long as the astronaut is on Earth, his weight is only
(68 kg) x (9.8 m/s²)
= 666.4 newtons .
Notice that his mass is his mass ... it doesn't change
no matter where he goes.
But his weight changes in different places, because
it depends on the gravity in each place.
Answer:
3 photons
Explanation:
The energy of a photon E can be calculated using this formula:

Where
corresponds to Plank constant (6.626070x10^-34Js),
is the speed of light in the vacuum (299792458m/s) and
is the wavelength of the photon(in this case 800nm).

Tranform the units

The band Gap is 4eV, divide the band gap between the energy of the photon:

Rounding to the next integrer: 3.
Three photons are the minimum to equal or exceed the band gap.