To work with consistent units, you need to convert 69.8 km/h to m/s, namely
69.8 km/h * 1000 m/km / 3600 s/h
= 69.8*1000/3600 km*m*h/(h*km*s)
= 19.39 m/s
After that, solve for a in F=ma, where F and m are known.
The time required in seconds can be obtained by dividing 19.39 m/s by the acceleration in m/s².
A heavy freight train has a mass of 14000 metric tons. If the locomotive can pull with a force of 645000 N, how long does it take to increase it's speed from 0 to 69.8 km/h?
1 answer