Physics
posted by y912f on .
please show me how to solve this
1. A bus travels 280 km south along a straight path with an average velocity of 88 km/h to the south. the bus stops for 24 min. then, it travels 210 km south with an average velocity of 75 km/h to the south
a. how long does the total trip last?
answer=6.4 h
b. what is the average velocity for the total trip?
answer=77 km/h to the South
thanks to whoever helps=]

a. Add the times requred for each of the two driving intervals, and add 24 minutes (0.4 hours) to that sum.
For each driving inteveral, use the reationship
time = distance)/(average speed
The sum will be the total driving and waiting time. Call it T.
b. Divide (280 + 210)km by T
That is how to do it. You do the numbers. 
ok thanks

so is this what i do:
280+210[how much they traveled]=490
then add .4 hours = 490.4
then :
T=490.4[distance]/average speed so 81.5?
my answer comes out 6.01 hours
i think im still doing something wrong 
the last post was by y912f not mysterychicken

You did not follow my instructions. You cannot add distance (km) to time (hours) in physics. It makes no sense.
The total time is
T = 280/88 + 0.4 + 210/75 = 6.38 hours