A system for which there are no outside effects is said to be ______________
Fill in the blank(s) with correct word
isolated
You might also like to view...
Which one of the following conditions is not a requirement for a particle to experience a magnetic force when placed in a magnetic field?
a) The particle must be moving. b) The particle must be charged. c) The particle must not be under the influence of any other forces. d) The velocity of the particle must have a component that is perpendicular to the direction of the magnetic field.
What is buoyancy?
What will be an ideal response?
Which of the following best explains why we can rule out the idea that planets are usually formed by near collisions between stars?
A) Stellar near collisions are far too rare to explain all the planets now known to orbit nearby stars. B) Studies of the trajectories of nearby stars relative to the Sun show that the Sun is not in danger of a near collision with any of them. C) A near collision might have created planets, but it could not have created moons, asteroids, or comets. D) A near collision should have left a trail of gas extending out behind the Sun, and we see no evidence of such a trail.
A thin, flat plate integrated circuit of 5 mm thickness is cooled on its upper surface by a dielectric liquid. The heat dissipation rate from the chip is 20,000 W/m2 and with the coolant flow at a free stream temperature of T?,l =250C, the convective heat transfer coefficient between the chip surface and the liquid is 1000 W/(m2 K). On the lower surface, the chip is attached to a circuit board, where the thermal contact resistance between the chip and the board is 10-4 m2.K/W. The thermal conductivity of board material is 1.0 W/m. K, and its other surface ( away from the chip) is exposed to ambient air at T?,a =200C where it is cooled by natural convection with the heat transfer coefficient of 30 W/(m2 K). (a) Determine the chip surface temperature under steady state condition for the
described conditions. (b) If the maximum chip temperature is not to exceed 750C, determine maximum allowable heat flux hat is generated by the chip. (c) A colleague suggests that in order to improve the cooling, you use a high conductivity bonding base at chip-board interface that would reduce the thermal contact resistance at the interface to 10-5 m2.K/W. Determine the consequent increase in the chip heat flux that can be sustained.
GIVEN
FIND
(a) Chip surface temperature under steady state condition
(b) Maximum allowable heat flux generated by the chip
(c) Consequent increase in chip heat flux if high conductivity bonding is used.
ASSUMPTIONS
Steady state conditions prevail
The thermal conductivity of the wall (k) is constant
One dimensional conduction
Negligible radiation and thermal resistance between chip surface and the liquid.
SKETCH
The thermal circuit of problem is given by
