Question

A car traveling 95km/h is 110m behind a truck traveling 75km/h. How long will it take the car to reach the truck?

Answer 1

since the car is 110 m behind or .11 km behind.

let t = time

the trucks distance traveled is 75t + .11 km (since it has a .11 km lead).

the car's distance traveled is 95t.

the car catches up to the train when their distance are equal so:

75t + .11 = 95t

.11 = 95t - 75t

20t = .11

t = .0055 h

to convert to seconds: 60 sec = 1 min, 60 min = 1 hr or 3600 sec/hr.

so .0055 * 3600 = 19.8 seconds.

Answer 2

The car is 'gaining' on the truck at (95-75) = 20 km/hr.

(110 m) / (20,000 m/hr) =

(110/20,000) hour =

0.0055 hour .

To get a better feel for that amount of time, convert units:

(0.0055 hour) x (60 min/hr) x (60 sec/min) =

(0.0055 x 3,600) sec = 19.8 seconds