Question

A car traveling at a rate of 30 ft/sec is approaching an intersection. When the car is 120 ft from the intersection, a truck traveling at a rate of 40 ft/sec crosses the intersection. If the roads are at right angles to each other, how fast are the car and the truck separating 2 seconds after the truck crosses the intersection?

Answer 1

Answer:

how fast are the car and the truck separating 2 seconds after the truck crosses the intersection: = 140ft

Explanation:

A car traveling at a rate of 30 ft/sec is approaching an intersection.

When the car is 120 ft from the intersection,

a truck traveling at a rate of 40 ft/sec crosses the intersection.

If the roads are at right angles to each other,

how fast are the car and the truck separating 2 seconds after the truck

for the car,

speed = distance/time

30 = 120/time

when the car is at 120ft to the intersection, he will used  t = 4sec to the intersection

for every 1sec, the car move 30ft

for the truck

speed = distance/time

40 = d/2sec

the distance of the truck at 2sec = 80ft

how fast are the car and the truck separating 2 seconds after the truck crosses the intersection: = 140ft

the car will be 60ft to the intersection and the truck will be 80ft after the intersection

therefore, the distance between the car and truck = 60+80 = 140ft