Some people believe that the moon’s phases are caused by earth’s shadows on the moon. is this true?

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error

In a voltaic cell, electrons flow from the (positive/negative) to the (positive/negative) terminal.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.