Imagine that an external force of 100 N must be applied to keep a bicycle and rider moving at a constant speed of 12 mi/h against opposing air drag. To double the bike’s speed to 24 mi/h, we must increase the magnitude of the force exerted on the bike to
A. 141 N
B. 200 N
C. 400 N
D. It depends on the bike’s shape and area
E. Other (specify)
C. 400 N
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Which of the following is FALSE?
a) Light, radio, ultraviolet, and gamma rays are all forms of electromagnetic radiation. b) Emission spectra are characterized by narrow, bright lines of different colors. c) An absorption spectrum appears as a continuous spectrum interrupted by a series ofdark lines. d) The energy of a photon is inversely proportional to the wavelength of the radiation. e) The wavelengths of the emission lines produced by an element are different from thewavelengths of an absorption line produced by the same element.
A long solenoid has a radius of 2.0 cm and has 700 turns/m. If the current in the solenoid is decreasing at the rate of 8.0 A/s, what is the magnitude of the induced electric field at a point 2.5 cm from the axis of the solenoid?
a. 56 mV/m b. 8.8 mV/m c. 88 mV/m d. 69 mV/m e. 44 mV/m
Dielectrics: A 15-?F capacitor is connected to a 50-V battery and becomes fully charged. The battery is removed and a slab of dielectric, having a dielectric constant of 5.0, is inserted between the plates and completely fills the space between them.(a) What is the capacitance of the capacitor after the slab is inserted?(b) What is the potential difference across the capacitor with the dielectric inserted.
Fill in the blank(s) with the appropriate word(s).
A 50. cm diameter wheel is rotating initially at 2.0 revolutions per second. It slows down uniformly and comes to rest in 15 seconds
(a) What was its angular acceleration? (b) Through how many revolutions did it turn in those 15 s?