Một lượng khí oxy khối lượng 160g được nung nóng từ nhiệt độ 50ºC đến 60ºC. Tìm nhiệt lượng mà khi nhận được và độ biến thiên nội năng của khối khí trong hai quá trình: a. Đẳng tích
b. Đẳng áp

Two students, each riding bicycles, start from the same apartment building and ride to the same building on campus, but each takes a different route. the first student rides 1100 m due east and then turns due north and travels another 1430 m before arriving at the destination. the second student heads due north for 1930 m and then turns and heads directly toward the destination.at the turning point, how far is the second student from the destination?

You are your friend move a new refrigerator into his kitchen. you apply a horizontal force of 252 n in the negative x direction to try and move the 56 kg refrigerator. the coefficient of static friction is 0.61. (a) how much static frictional force does the floor exert on the refrigerator? give both magnitude (in n) and direction. magnitude n direction (b) what maximum force (in n) do you need to apply before the refrigerator starts to move?

How can you improve the percent yield of copper in this lab? check all possible strategies that will you do so. measure reactants precisely. stir to the reaction take place. chill the reactants before combining them. wait patiently until the reaction completes. make sure to recover as much copper as possible.