A bucket in an old well is hoisted upward by a rope which winds up on a cylinder having a radius of 0.05 m. How many rev/s must the cylinder turn if the bucket is raised at a speed of 0.25 m/s?

Asmall metal bar, whose initial temperature was 10° c, is dropped into a large container of boiling water. how long will it take the bar to reach 70° c if it is known that its temperature increases 2° during the first second? (the boiling temperature for water is 100° c. round your answer to one decimal place.) sec how long will it take the bar to reach 98° c? (round your answer to one decimal place.)

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above

Which of these metals are magnetic?