Which is the weakest of the four fundamental forces? strong nuclear weak nuclear electromagnetic gravitational

An electron jumps from energy level 1 to energy level 2 by absorbing a photon of energy 8 eV. What is the most likely energy of the photon that will be emitted by the electron when it moves back down to energy level 1? A 2 eV B 4 eV C 8 eV D 12 eV

Select the correct answer. Which statement about nuclear fusion is correct? A. Two hydrogen electrons become protons during fusion. B. Helium nuclei can fuse to form elements such as nitrogen. C. The fusion reaction lasts for several hundred years. D. Large nuclei break apart to form smaller nuclei.

For a given motor vehicle, the maximum achievable deceleration from braking is approximately 7m/sec^2 on dry concrete. On wet asphalt, it is approximately 2.8m/sec^2 Given that 1 mph corresponds to 0.447m/sec find the total distance that a car travels in meters on dry concrete after the brakes are applied until it comes to a complete stop if the initial velocity is 67 mph (30m/sec) or if the initial braking velocity is 56 mph (25m/sec) (Round your answers to one decimal place.) 67 mph (30m/sec) square lm 56 mph (25m/sec) square m Find the corresponding distances if the surface is slippery wet asphalt. 67 mph (30m/sec) square lm 56 mph (25m/sec) square lm

When electrons are forced to move through a conductor, the magnetic fields of individual electrons subtract from one another. True False

Voltmeters are connected in __ with the circuit and measure the difference of potential between the two test leads. series parallel series-parallel none of these

The electric motor works on the principle of the attracting and repelling forces of __ fields. voltage current power magnetic

When lodestones were suspended by a piece of string, they always point in the same direction. True False

Which features does the video contain that contributed to your knowledge of black holes? Check all that apply. It has a narrator. It has textual information. It has computer graphics. It has interactive elements. D It has charts and graphs.

A type of mechanical energy that is possessed by an object in motion. Kinetic energy Gravitational potential energy Strain energy Force energy

Hot Questions

Which of the following describe the expansion coefficients for a general state? $a_{n}=\langle \psi _{n}\vert \psi \rangle =\int _{-\infty }^{\infty }dx\psi _{n}^{\ast }(x)\psi (x)$ $a_{n}=(\sum _{n}\vert \psi _{n}\rangle )\vert \psi \rangle $ $a_{n}=\langle \psi _{n}\vert \psi \rangle ^{\ast }=\int _{-\infty }^{\infty }dx\psi _{n}(x)\psi ^{\ast }(x)$ $a_{n}=\langle \psi _{n}\vert \psi _{m}\rangle =\int _{-\infty }^{\infty }dx\psi _{n}^{\ast }(x)\psi _{m}(x)$

A certain wave function is given by $\psi (x)=\{ \begin{matrix} A&for-a\leqslant x\leqslant a\\ 0&otherwise\end{matrix} $ Which of the following corresponds to the Fourier transform for this wave function? A sum of spherical harmonics. A sum of sines and cosines. A sum of Hankel functions. The Dirac delta function.

8> What is the random capture theory? Which theory best explains how our solar system was created?

A wave function can be expanded in basis states as $\vert \psi \rangle =\sum _{n}a_{n}\vert \psi _{n}\rangle $ What must be true of the expansion coefficients? $\sum _{n}\vert a_{n}\vert ^{2}=1$ They must be real numbers. There is no restrictions on the coefficients. $\sum _{n}a_{n}=1$

Match each statement to the wave interaction it describes. \begin{array}{|l|l|} \hline\ reflection\ &\ Waves\ bounce\ off\ an\ object.\ \\ \hline\ absorption\ &\ Waves\ are\ taken\ in\ by\ an\ object.\ \\ \hline\ transmission\ &\ Waves\ bend\ while\ passing\ from\ one\ medium\ to\ another.\ \\ \hline\ diffraction\ &\ Waves\ scatter\ through\ an\ opening\ or\ around\ an\ object.\ \\ \hline\ retraction\ &\ Waves\ go\ through\ an\ object.\ \\ \hline \end{array}

Which of the following expressions correspond to the energy-time uncertainty principle? $\Delta E\Delta t\geqslant 2\bar {h}$ $\Delta E\Delta t\geqslant \hat {h}$ $\Delta E\Delta t\geqslant \frac {h}{2}$ $\Delta \omega \Delta t\geqslant \bar {h}$

Consider the following force: A fridge magnet is pulling on a paper clip. According to Newton's third law what other force must be happening? The paper clip is pushing on the fridge magnet. The paper clip is pulling on the fridge magnet.

Which of the following correspond to the first-order shift in energies using time-independent perturbation theory? $\vert \langle \psi _{n}^{0}\vert \delta \hat {H}\vert \psi _{n}^{0}\rangle \vert ^{2}$ $\langle \psi _{n}^{0}\vert \delta \hat {H}\vert \psi _{n}^{0}\rangle $ $\sum _{m\neq n}\frac {\langle \psi _{n}^{0}\vert \delta \hat {H}\vert \psi _{n}^{0}\rangle }{E_{m}^{0}-E_$ $\sum _{m\neq n}\frac {\vert \langle \psi _{m}^{o}\vert \delta \hat {H}\vert \psi _{n}^{o})\vert ^{2}}{E_{m}^$

Which one of the following actions will increase the current ratio, all else constant? Assume the current ratio is greater than 1.0

If a wave function is given in terms of orthonormal wave functions as $\vert \psi \rangle =\frac {1}{\sqrt {5}}\vert \psi _{1}\rangle +\sqrt {\frac {3}{5}}\vert \psi _{2}\rangle +A\vert \psi _{3}\rangle $ Then what must be true about A? $\frac {1}{\sqrt {5}}$ $\frac {1}{2}$ There is not enough information to determine A. $\frac {1}{5}$