an automobile 16 feet long overtakes a truck that is 28 feet long and is traveling 30 mph. At what rate must the automobile travel to pass the truck in 4 seconds?

Automobile must travel at 96 mph to pass the truck in 4 seconds.

Step-by-step explanation:

Length of automobile = 16 feet = 4.88 m

Length of truck = 28 feet = 8.53 m

Speed of truck = 30 mph = 48 km/h = 13.33 m/s

Time in which automobile to pass truck = 4 s

Distance traveled by truck in 4 seconds = 4 x 13.33 = 53.33 m

Distance which need to cover by automobile in 4 seconds to pass truck is the sum of length of automobile, length of truck and distance traveled by truck in 4 seconds.

Distance which need to cover by automobile in 4 seconds = 4.88 + 8.53 + 53.33

Distance which need to cover by automobile in 4 seconds = 66.74 m

Distance = Speed x Time

66.74 = Speed x 4

Speed = 16.69 m/s = 60 km/h = 96 mph

Automobile must travel at 96 mph to pass the truck in 4 seconds.