1.
17. Tripling the mass per unit length of a guitar string will result in changing the wave speed in
the string by what factor? a. 1.73 b. 1.00 (i.e., no change) c. 3.00 d. 0.58 18. An ion is released
from rest and moves due to the force from an electric field from a position in the field having a
potential of 14 V to a position having a potential of 8 V. The ion: a. must have a negative charge.
b. can have either a positive or a negative charge. c. must have a positive charge. d. must be
neutral.
Solution
17)
wave speed v = sqrt(F/u)
if mas per unit length(u) is trippled
wave speed v' = v/sqrt3 = v*0.58
the speed chnages by a factor of 0.58
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18)
positive charge always moves from high potential to low potential
negative charge moves from low potential to high potential
here the charge is moving fro high ( 14 V ) to low potential ( 8 V)
the ion must have poisitive charge <<<-------------ANSWER