Answer:a) 492 nm; b) 1.78 eV
Explanation: In order to solve this problem we have to use the photoelectric energy balance givenb by:
h*ν=Ek+W where h is the Placnk constant, ν is the frequency of the radiation, Ek is the kinetic energy of the realised electrons and W is the work funcion of the incident metal.
Then we have:
W=h*ν-Ek= h*c/λ-Ek=1240 eV.nm/176 nm=2.52 eV
so the maximun wavelength to realese the electrons is when Ek=0 then
W=h*c/λmax so λmax= h*c/W= 1240/2.52=492.06 nm
Finally if we use 288 nm to realease the electrons, then Ek of the emitted electron from the metal is:
from h*ν=Ek+W we have:
Ek=h*c/λ-W= (1240/288) eV*nm-2.52 eV=1.78 eV
Answer:
25J
Explanation:
Given parameters:
Mass of the dog = 10kg
Speed of the dog = 5m/s
Unknown:
The minimum energy required to stop the dog = ?
Solution:
The dog is moving with a kinetic energy and to stop the dog, an equal amount of kinetic energy generated must be applied to the dog.
To find the kinetic energy;
K.E = m v²
m is the mass
v is the velocity
Now insert the parameters and solve;
K.E = x 10 x 5 = 25J
<span>Answer:The iliopsoas muscle
</span>The
iliacus and the psoas major muscles, together are known as the iliopsoas muscle. That's because they share a common insertion on the small trochanter of the femur. However, they have different origins, making them two different muscles. Together, they are strong flexors of the hip.
Answer:
0 N
Explanation:
suppose, you push a box with 5 N, and another person pushes the box on the opposite side of the box with 5 N, the net force (resultant ) is 0 N, the box will not move if it wasn't moving
hope this helps
Hello, I don't see a table, but I am guessing that you are referring to the one I attached (below).
Answer:
So, the correct order of events sorted chronologically is:
<u>
1. A nebula located in the Milky Way galaxy begins pulling nearby hydrogen atoms in its orbit.
</u>
2. The Nebula shrinks in its volume due to gravity, becoming denser and hotter. But, it's not hot enough for nuclear fusion.
<u>
3. The temperature in the core of the Nebula reaches 14 million Kelvin.
</u>
4. Hydrogen atoms begin shedding their electrons and colliding with one another.
5. The Sun enters the main sequence stage. The energy created as a result of its radiation begins nurturing life on planet such as Earth.
6. The Sun uses up all the hydrogen in its core.
<u>
7. The Sun expands greatly and cools. It is larger and redder.
</u>
8. The Sun completely runs out of hydrogen to fuse. Its outer layers are pushed away, and a cloud of ionized gas surrounds its core.
<u>
9. The Sun is a white dwarf with a dim glow.</u>
Hope this helps!