Answer:
![5.07\cdot 10^{-14} m](https://tex.z-dn.net/?f=5.07%5Ccdot%2010%5E%7B-14%7D%20m)
Explanation:
The velocity of the neutrons is
![v=3.13\cdot 10^7 m/s](https://tex.z-dn.net/?f=v%3D3.13%5Ccdot%2010%5E7%20m%2Fs)
The mass of a neutron is
![m=1.66\cdot 10^{-27} kg](https://tex.z-dn.net/?f=m%3D1.66%5Ccdot%2010%5E%7B-27%7D%20kg)
So their momentum is
![p=mv=(1.66\cdot 10^{-27})(3.13\cdot 10^7)=5.20\cdot 10^{-20}kg m/s](https://tex.z-dn.net/?f=p%3Dmv%3D%281.66%5Ccdot%2010%5E%7B-27%7D%29%283.13%5Ccdot%2010%5E7%29%3D5.20%5Ccdot%2010%5E%7B-20%7Dkg%20m%2Fs)
The relative uncertainty on the velocity is 2 %. Assuming that the mass of the neutron is known with negligible uncertainty, then the relative uncertainty on the momentum of the neutron is equal to the relative uncertainty on the velocity, so 2%. Therefore, the absolute uncertainty on the momentum is
![\sigma_p = 0.02 p =0.02(5.20\cdot 10^{-20})=1.04\cdot 10^{-21} kg m/s](https://tex.z-dn.net/?f=%5Csigma_p%20%3D%200.02%20p%20%3D0.02%285.20%5Ccdot%2010%5E%7B-20%7D%29%3D1.04%5Ccdot%2010%5E%7B-21%7D%20kg%20m%2Fs)
Heisenber's uncertainty principle states that
![\sigma_x \sigma_p \geq \frac{h}{4\pi}](https://tex.z-dn.net/?f=%5Csigma_x%20%5Csigma_p%20%5Cgeq%20%5Cfrac%7Bh%7D%7B4%5Cpi%7D)
where
is the uncertainty on the position
h is the Planck constant
Solving for
, we find the minimum uncertainty on the position:
![\sigma_x \geq \frac{h}{4\pi \sigma_p}=\frac{6.63\cdot 10^{-34}}{4\pi(1.04\cdot 10^{-21})}=5.07\cdot 10^{-14} m](https://tex.z-dn.net/?f=%5Csigma_x%20%5Cgeq%20%5Cfrac%7Bh%7D%7B4%5Cpi%20%5Csigma_p%7D%3D%5Cfrac%7B6.63%5Ccdot%2010%5E%7B-34%7D%7D%7B4%5Cpi%281.04%5Ccdot%2010%5E%7B-21%7D%29%7D%3D5.07%5Ccdot%2010%5E%7B-14%7D%20m)
Answer:
Electromagnetic field, a property of space caused by the motion of an electric charge. A stationary charge will produce only an electric field in the surrounding space. If the charge is moving, a magnetic field is also produced. An electric field can be produced also by a changing magnetic field.
If you are in this kind of geographical scenery, you must be on a surfing beach in California. The Californian coastline is characterized by a numerous number of beaches that are mainly sandy and features major rivers such as the Sacramento River and the Colorado River.
Answer:
a. Temperatures increase can change a solid to a liquid, but cannot change a liquid to a solid
b. The particles in a solid are much closer together than the particles in a liquid.
Explanation:
Any material expands when heated and contracts when cooled. So, when a body is heated to a particular temperature, it starts melting and changes into a liquid.
As the material expands the distance between the atoms or molecules increases and it will become a liquid. So it can move around the material. It doesn't become solid on further heating. But water is an exception where it contracts when heated from 0° to 4° C.
In solids, these atoms or molecules are closely packed. It is rigidly fixed.
The solid, as well as the liquid, has a definite volume, but the liquid does not have a definite shape.