A 25-tons freight car ran into another freight car of the same mass. The first moves at 2.7 m/s and the second moved towards the first at the speed 0.5 m/s. If the cars were coupled
together after the collision, what was their final speed?

Rank the torques on the five doors shown in the figure above from least to greatest. note that the magnitude of all the forces is the same

A20 cm long spring is attached to a wall. the spring stretches to a length of 22 cm when you pull on it with a force of 100 n. what is the spring constant

The california mussel (mytilus californianus) attaches itself to a rock or other solid surface with a bundle of filaments known as the byssus. imagine that 15.0 j of work is done to stretch the distal end of the byssus. it releases 10.8 j of thermal energy as it relaxes. what is the resilience of the distal end of the byssus?