#### Answer

a). $38m$
b). $53m$

#### Work Step by Step

m=1500kg
speed=90km/hr=25m/s
coefficient of friction for dry pavement = 0.85
coefficient of friction for wet pavement = 0.60
a). $a=\frac{coefficient \,of\, friction \,in\, dry\, pavement\, \times mg}{m}=0.85\times9.8=8.3m/s^{2}$
Now, $v^{2}=u^{2}+2aS$
$0=25^{2}-2\times8.3S$
$S=38m$
b). $a=\frac{coefficient \,of\, friction \,in\, wet\, pavement\, \times mg}{m}=0.60\times9.8=5.88m/s^{2}$
Now, $v^{2}=u^{2}+2aS$
$0=25^{2}-2\times5.88S$
$S=53m$