Zoe has drawn a 5 cm long vector pointing down. She says this represents an acceleration of 10 m/s2 down. Which scale did she use?

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Consider a hydrogen atom in the ground state. what is the energy of its electron? =e= jj now consider an excited‑state hydrogen atom. what is the energy of the electron in the =5n=5 level? =e5= j

The bar of prob. 5/82 is repeated here. the ends of the 0.4-m bar remain in contact with their re- spective support surfaces. end b has a velocity of 0.5 m/s and an acceleration of 0.3 m/s2 in the di- rections shown. determine the angular accelera- tion of the bar and the acceleration of end a.