In anticipation of a long 6° upgrade, a bus driver accelerates at a constant rate from 80 km/h to 100 km/h in 8 s while still on a level section of the highway. Knowing that the speed of the bus is 100 km/h as it begins to climb the grade at time t= 0 and that the driver does not change the setting of the throttle or shift gears, determine (a) the speed of the bus when t= 10 s, (b) the time when the speed is 60 km/h.

In anticipation of a long 6° upgrade, a bus driver accelerates at a constant rate from 80 km/h to 100 km/h in 8 s while still on a level section of the highway. Knowing that the speed of the bus is 100 km/h as it begins to climb the grade at time t= 0 and that the driver does not change the setting of the throttle or shift gears, determine (a) the speed of the bus when t= 10 s, (b) the time when the speed is 60 km/h.