SERCP$117\mathrm{.}4.$P$\mathrm{.}032.$

A roller$-$coaster vehicle has a mass of $530$ kg when fully loaded with passengers $($see figure$).$

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$($a$)$ If the vehicle has a speed of $15\mathrm{.}0\frac{m}{s}$ at point $(A),$ what is the force $($in N $)$ of the track on the vehicle at this point?

$$ N

$($b$)$ What is the maximum speed $($in $\frac{m}{s})$ the vehicle can have at point $B$ in order for gravity to hold it on the track?

$$ m$/$s