Apolice car is parked by the side of a highway and its siren emits a sound measuring 750 hz. as you approach the police car from a distance, you hear a change in the sound. the change is in the sound's

If there's a small amount of friction between two surfaces, the result could be select all that applya. no movement b. heatc. a little bit of movementd. sliding around

Which of the following are molecules? a. al b. ag c. mgcl2 d. nacl e. c3h8

Asquare isothermal chip is of width w=5 mm on a side and is mounted in a substrate such that its side and back surfaces are well insulated; the front surface is exposed to the flow of a coolant at tinf=15 °c. from reliability considerations, the chip temperature must not exceed t=85 °c. if the coolant is air and the corresponding convection coefficient is h=200 w/m2 x k, what is the maximum allowable "power" of the chip? if the coolant is a liquid for which h=3000 w/m2 x k, what is the maximum allowable power of the chip?