What happens to wavelength if frequency is multiplied by 4?

The gravitational attraction between two objects will if one object acquires more mass .

From center station, a train departs every 30 minutes on the fast line and a train departs every 50 minutes on the state line. if two trains depart from center station at 8: 00 a.m., one on each of the two lines, what is the next time that two trains, one on each line, will depart at the same time?

Jessie ran 5000 meters from the cops and an average speed of 6 meters / second before he got caught . how long did he run?