Suppose I push a block along a tabletop at a constant velocity. If I exert a constant forward force of 
on the block and push it through a distance D, I do work on the block equal to ?F?D. Since the block’s kinetic energy does not change, friction must be exerting a backward force on the block of the same magnitude as 
(so that the net force on the block is zero, as required to maintain the block’s constant velocity). What work does the friction force do on the block?
A. No work
B. ? 
D
C. + D
D. Some negative work, but we need more information to determine exactly how much.
E. Some positive work, but we need more information to determine exactly how much.
D. Some negative work, but we need more information to determine exactly how much.
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Nuclear Binding Energy: The carbon in our bodies was formed in nuclear reactions in long-dead stars. How much energy was released when the right number of 4He nuclei combined to make 12C? The mass of 4He is 3728.40 MeV/c2 and the mass of 12C is 11,177.93 MeV/c2.
A. 7.27 MeV B. 372 MeV C. 8.42 MeV D. 2.11 MeV
Diffraction Gratings: When a diffraction grating having 5000 lines/cmis illuminated by monochromatic light, the angle between the central maximum and the fourth order maximum is 47.2°. What is the wavelength of the light?
A. 138 nm B. 183 nm C. 367 nm D. 637 nm
__________is an apparent change in the wavelength of radiation caused by relative motion of a source and observer
A) The black drop effect B) The Doppler effect C) The Casimir effect D) The common ion effect
The observed composition of ordinary matter in the universe—roughly 75 percent hydrogen and 25 percent helium by mass—closely matches theoretical predictions based on the Big Bang model
Indicate whether the statement is true or false