Gravity is the cause of . . .
-- star formation,
-- planet formation,
-- orbits.
So without gravity, there pretty much wouldn't be any solar or any system.
Explanation:
The Net Force of the object can be written by:
Fnet = ma
where m is the mass of the object in <em>kg</em>
a is the acceleration of the object in <em>m/s^2</em>
Hence by applying the formula we get:
Fnet = (2.0)(3.0)
= 6N
We also know that Net force is also the sum of all forces acting on an object. In this case Friction and the Pushing Force is acting on the object. Hence we can write that:
Fnet = Pushing Force + (-Friction)
6N = 6N - Friction
Friction = 0N
Hence the<u> </u><u>f</u><u>orce of friction is 0N.</u>
Answer:
True
Explanation:
Just as Isaac Newton says, "For every action, there is an equal and opposite reaction."
Answer: a) 274.34 nm; b) 1.74 eV c) 1.74 V
Explanation: In order to solve this problem we have to consider the energy balance for the photoelectric effect on tungsten:
h*ν = Ek+W ; where h is the Planck constant, ek the kinetic energy of electrons and W the work funcion of the metal catode.
In order to calculate the cutoff wavelength we have to consider that Ek=0
in this case h*ν=W
(h*c)/λ=4.52 eV
λ= (h*c)/4.52 eV
λ= (1240 eV*nm)/(4.52 eV)=274.34 nm
From this h*ν = Ek+W; we can calculate the kinetic energy for a radiation wavelength of 198 nm
then we have
(h*c)/(λ)-W= Ek
Ek=(1240 eV*nm)/(198 nm)-4.52 eV=1.74 eV
Finally, if we want to stop these electrons we have to applied a stop potental equal to 1.74 V . At this potential the photo-current drop to zero. This potential is lower to the catode, so this acts to slow down the ejected electrons from the catode.
Imagine you are in a swimming pool 30m deep. Assuming you know that water is denser than air, you would know that the 30m of water above you will carry more weight, and press down on your body. Say you were in a swimming pool 60m deep, you would be sandwiched between 30m of water pressing down on you, and the upthrust created by the 30m of water below you.
In a building 30m up, the pressure will be regulated, as you are in a building. The floor will be strong enough to support the weight of the body, and the body will not recoil into itself.
