A.    3.72 m/s

B.    13.9 m/s

C.    118 m/s

D.    177 m/s

Force P = mg Sin 45^o

To keep the car on the track,

the centripetal force must equal Force P

    
                                  mv
Centripetal Force = -----
                                    r

                         mv²                                 v²  
mg Sin 45^o =  -------     =>  g Sin 45^o =  ----
                          r                                     r

v = ( rg Sin 45^o) ^1/2  =  (2.00 x 10³ m x 9.80 m/s² x Sin 45^o) ^1/2

v = 118 m/s