Atrain travels 57 kilometers in 3 hours, and then 87 kilometers in 2 hours. what is its average speed? km/hr

6–48 bananas are to be cooled from 24 to 138c at a rate of 215 kg/h by a refrigeration system. the power input to the refrigerator is 1.4 kw. determine the rate of cooling, in kj/ min, and the cop of the refrigerator. the specific heat of banana above freezing is 3.35 kj/kg·8c.

Place several e-field sensors at a few points on different equipotential lines, and look at the relationship between the electric field and the equipotential lines. which statement is true? 1-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of higher voltages. 2-at any point, the electric field is perpendicular to the equipotential line at that point, and it is directed toward lines of lower voltages. 3-at any point, the electric field is parallel to the equipotential line at that point.

It's time for santa to deliver his presents. assuming he delivers presents all over the world, he has to travel about 75,000,000 miles. if he travels east to west, he can use the time zones to make christmas day last 31 hours. what speed, in miles per hour, must santa fly to get all of his presents delivered?