Klint and Matt decided to race go-Karts down the hill at their house. The mass of Matt's go-Kart is 86kg. Klint's cart falls apart halfway down the hill. Matt's go-cart makes it all the way to the bottom in 40 seconds. If the total distance of the hill is 80 feet, what is the acceleration of his go-cart?

Respuesta :

AL2006

All we can say from the given information is that Matt's
average speed from the top to the bottom is

                (80 feet) / (40 seconds)  =  2 feet per second .

We're not told whether his acceleration was constant
all the way down.  IF it was, then we could use

                               Distance = (1/2 acceleration) x (time²).

                                      80 ft  =  (1/2 acceleration) x (40 sec)²

Divide each side
by 1600 sec² :             80 ft / 1600 sec² = 1/2 acceleration

Multiply each side
by  2:                           160 ft / 1600 sec² =        acceleration

                                            Acceleration  =  0.1 ft/sec² .