False . accelerating means to increase but moving at a constant speed means you stay the same .
Explanation:
As the earth travels around the sun in the elliptical orbit it must also be know that the axis of the earth is tilted as well.
- So when the earth is at the farthest point and the tilt of the earth's axis is towards the sun in that case the sun rays always incident on the surface of the earth near the poles and hence there is sunlight for the 24 hours of the day. But the intensity of these rays is very low because of the their slanted angle of incident. In other words the same sun rays cover a larger area and the luminous intensity is reduced.
- When the earth is near to the sun we have an increased average temperature of the day during that phase giving us an experience of summer season and vice-versa is the condition in winter seasons. The tilt of the earths axis is responsible for variation in extremities of the seasons with respect to the geographical location.
Answer:
the answer would be "using more heat" btw
Explanation:
<em>"A concave lens is thinner at the center than it is at the edges."</em>
If this isn't on the list of choices, that's tough. We can't help you choose the best one if we don't know what any of them is.
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.
