Final answer:
To determine how many miles a car will travel in 5 hours at a constant speed, first find its average speed, which is 60 mph. Then, multiply the average speed by the time, which results in 300 miles.
Step-by-step explanation:
If a car travels 90 miles in 1.5 hours, to find out how many miles it will travel in 5 hours at the same speed, first calculate the average speed of the car. The average speed Vavg is the distance traveled divided by the time it takes to travel that distance. So for this problem:
Vavg = distance / time = 90 miles / 1.5 hours = 60 mph.
Now, to find out how far the car will go in 5 hours at this speed:
Distance = Speed × Time = 60 mph × 5 hours = 300 miles.
Thus, the car will travel 300 miles in 5 hours if its speed remains the same.