Atrain travels 120km in 2 hours and 30 minutes what is the average speed

Aball is thrown from the top of a building with an initial velocity of 21.9 m/s straight upward, at an initial height of 51.6 m above the ground. the ball just misses the edge of the roof on its way down, as shown in the figure. (a) determine the time needed for the ball to reach its maximum height. (b) determine the maximum height. (c) determine the time needed for the ball to return to the height from which it was thrown, and the velocity of the ball at that instant. (d) determine the time needed for the ball to reach the ground. (e) determine the velocity and position of the ball at t = 5.35 s.

All phase changes are .an example of a phase change is an ice cube melting

The potential energy for a mass on a spring is proportional to the square of which of these quantities? a. mass b. frequency c. period d. displacement e. velocity