15. How can scientists detect dark energy using evidence? Scientists can see the bending of light due to the gravitational force of matter that cannot otherwise be detected. Scientists have detected dark matter in experiments. Scientists can see dark energy directly through ordinary light waves.

Which of these statements is most likely correct about a weak nuclear force? (2 points) It binds electrons and protons. It is a repulsive force. It is an attractive force. It binds protons and neutrons.

Which side of the electromagnetic spectrum has shorter waveiengths? $\square $ Which side of the electromagnetic spectrum has higher energy? $\square $ Which side of the electromagnetic spectrum has higher frequencies? $\square $ blue

Outdoors, shadows are longest at what time of day? Midnight Sunrise and sunset Noon 10 a.m.

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?

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}

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. $\sum _{n}a_{n}=1$

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.