A train took 7 hours to complete its journey . For the first 3 hours it's average speed was 155km/h , for the remaining travel , the average speed was 186 km/h , what was the total distance ?

The 10-kg double wheel with radius of gyration of 125mm about o is connected to the spring of stiffness k = 600 n/m by a cord which is wrapped securely around the inner hub. if the wheel is released from rest on the incline with the spring stretched 225 mm, calculate the maximum velocity v of its center o during the ensuing motion. the wheel rolls without slipping

In science and physics what is the standard unit of measure for speed?

The ozone hole appears in antarctica during