Two plane coaxial disks are separated by a distance 0.6 m. The lower disk is solid with a diameter 0.80 m and a temperature 300 K. The upper disk , at temperature 900 K, has the same outer diameter but is ring-shaped with an inner diameter 0.40 m. Assuming the disks to be blackbodies, calculate the net rate of radiative heat exchange from disk 1 to disk 2, in kW.

An alligator swims to the left with a constant velocity of 5 \,\dfrac{\text{m}}{\text s}5 s m ? 5, space, start fraction, m, divided by, s, end fraction. when the alligator sees a bird straight ahead, the alligator speeds up with a constant acceleration of 3 \,\dfrac{\text {m}}{\text s^2}3 s 2 m ? 3, space, start fraction, m, divided by, s, start superscript, 2, end superscript, end fraction leftward until it reaches a final velocity of 35 \,\dfrac{\text {m}}{\text s}35 s m ? 35, space, start fraction, m, divided by, s, end fraction leftward. how many seconds does it take the alligator to speed up from 5 \,\dfrac{\text {m}}{\text s}5 s m ? 5, space, start fraction, m, divided by, s, end fraction to 35 \,\dfrac{\text {m}}{\text s}35 s m ? 35, space, start fraction, m, divided by, s, end fraction?

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is

Gasoline comes from petroleum, which is made from ancient living things. petroleum, therefore, contains a type of energy. a. heat b. nuclear c. biological d. chemical potential