You agree to build a backyard rope tow to pull your siblings up a 20-m slope that is tilted at 15 degrees relative to the horizontal. You must choose a motor that can pull your
40-kg sister up the hill. Determine the force that the rope should exert on your sister to
pull her up the hill at constant velocity.

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?