Question textA boy slides a heavy book toward his friend at the other end of a table that is 3.0 meter long . 1.0 meter of the table is highly polished; the rest is rough. The graph below shows the kinetic energy of the book versus distance along the table. The mass of the book is 1.4 kg. What is the initial velocity of the book? Answer: Answer 1 Question 2[input] m s-1 How much work was done against friction caused by the rough part of the table? Answer: Answer 2 Question 2[input] J What is the magnitude of the frictional force? Answer: Answer 3 Question 2[input] N His friend fails to catch the book, so the it goes over the edge and falls to the floor 0.90 meter below the table. What is the total energy of the book just before striking the floor? (neglect air resistance) J Answer: Answer 4 Question 2[input]多项填空题