The computation would be:moles = mass/ Molar Mass, but we are looking for the mass, so rearranging, will give us: mass = moles x MM Q = moles x Hf Q = (mass/MM) x Hf mass = (Q x MM) / Hf = (1.50-kJ x 18.0-g/mol) / 6.01-kJ/mol =4.49 g H20 is the answer
The box stopped moving because there was a negative acceleration in the x direction caused by friction. To find the average speed, simply divide the displacement by time: 10 / 2 = 5 m/s
