Suppose you have a $0\mathrm{.}750-$kg object on a horizontal surface connected to a spring

that has a force constant of $150$ N$/$m$.$ There is simple friction between the object and surface

with a static coefficient of friction s $=0\mathrm{.}100.($a$)$ How far can the spring be

stretched without moving the mass? $(2\mathrm{.}5$pt$)$

$($b$)$ If the object is set into oscillation with an amplitude twice the distance found in part $($a$),$ and

the kinetic coefficient of friction is k $=0\mathrm{.}0850,$ what total distance does it travel before

stopping? Assume it starts at the maximum amplitude. $(2\mathrm{.}5$pt$)$

Problem

$18$: Ear trumpets were never very common, but they did aid people with hearing losses by

gathering sound over a large area and concentrating it on the smaller area of the eardrum.

What decibel increase does an ear trumpet produce if its sound gathering area is $900$

cm$2$ and the area of the eardrum is $0\mathrm{.}500$ cm$2,$ but the trumpet only has an efficiency of $5\mathrm{.}00\%$

in transmitting the sound to the eardrum? $(5$pt$)$

$=$

d $=$