Pls help The Q : Look at your recorded results and models for both the man and the boy. How close are the coefficients of friction for the sled on ice for two runs? How confident would you feel about specifying a coefficient of kinetic friction for this sled on this ice surface, based on these results? What other variables might impact this coefficient result?

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.)

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

Which of the following are guidelines to follow for obtaining accurate observations