A 63 kg boy and sled are pulled along level ground with a force of 577 N. The boy and sled are moving at a constant velocity of 2.4 m/s. What is the size of the frictional force?

Imagine you had to physically add electrons, one at a time, to a previously neutral conductor. you add one electron very easily, but the second electron requires more work. in your initial post to the discussion, explain why this is. also, what happens to the work needed to add the third, fourth, fifth, and subsequent electrons

What are chlorofluorocarbons and what impact do they have on the atmosphere?

Which of the following is not a part of the respiratory system? a. pharynx b. trachea c. pancreas d. larynx