Asuspicious-looking man runs as fast as he can along a moving sidewalk from one end to the other, taking 2.90 s. then security agents appear and the man runs as fast as he can back along the sidewalk to his starting point, taking 10.7 s. what is the ratio of the man's running speed to the sidewalk's speed (running speed / sidewalk speed)?

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Two trains leave a station at the same time, train a travels at a constant speed of 16 m/s. train b starts at 8.0 m/s but accelerates constantly at 1.0 m/s squared. after 10.0 seconds, which train has the greater speed?

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?