Can someone help me please

Which best describes the idea behind the "invisible hand"? producers decide what to make for consumers, which guides the economy. individuals seeking their own self interest benefit the economy as a whole. government sets policy for producers and consumers, which guides the economy. consumers decide what they need and want to buy, which guides the economy.

How did european immigrants of the late 1800s change american society

Mr. mann's science students were experimenting with speed. they set up a 1 meter (100 cm) track. the students used balls instead of cars. the balls were different sizes and made of different materials. four at a time, students rolled balls around the track to see which had the fastest and slowest speeds. some of their data are shown in the table. which ball will take the longest to complete one lap around the track?