physics
posted by Victoria .
Please help!!!
A car travels 90.0 minutes on the highway. For the first 36.6 minutes it travels 76.5 km/h. It maintains 95.1 km/h for the remainder of the trip. What was the average speed of the vehicle in km/h?

t=90 min = 1.5 h
t1= 36.6 min =0.61 h
s1=v1•t1=76.5•0.61=46.665 km
t2=1.50.61= 0.89 h.
s2=95.1•0.89=84.639 km
s=s1+s2=46.665+84.639=131.304 km
Ave speed = s/t = 131.304/1.5 =87.536 km/h