A spherical wave travels outward from a point source. What is the phase difference between the two points on the wave marked by the dots?.

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.

We put a force of 50n on an object and the acceleration is 100 m/s². what is the mass of the object?

Polly is pushing a box across the floor with a force of 30 n. the force of gravity is –8 n, and the normal force is 8 n. which value could describe the force of friction if polly could not move the box?