Show that in general a skew-symmetric tensor such as the spin tensor W has only one real principal value λ. Determine λ and the corresponding direction ˆn in terms of the components w1 = −W23, w2 = −W31, w3 = −W12 of the vector ˆω.

In a good thermo flask the main cause of heat loss is

Amoving electron has kinetic energy k1. after a net amount of work w has been done on it, the electron is moving one-quarter as fast in the opposite direction. (a) find w in terms of k1. (b) does your answer depend on the final direction of the electron's motion?

Aball with a mass of 275 g is dropped from rest, hits the floor and rebounds upward. if the ball hits the floor with a speed of 2.40 m/s and rebounds with a speed of 1.70 m/s, determine the following. (a) magnitude of the change in the ball's momentum (let up be in the positive direction.)