Why Multiply by g?

• Autores: Nelson Bray
• Localización: The Physics Teacher, ISSN 0031-921X, Vol. 50, Nº. 3, 2012, pág. 161
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • As a new physics teacher, I was explaining how to find the weight of an object sitting on a table near the surface of the Earth. It bothered me when a student asked, �The object is not accelerating so why do you multiply the mass of the object by the acceleration due to gravity?� I answered something like, �That's true, but if the table were not there, the object would accelerate at that rate.� The really determined students might go on to ask, �Yes, but what if the object were already sitting on the surface of the Earth?� About that time, I would hope the bell would ring so that this whole discussion could be delayed until the next day. The next day, I would explain that the newton unit is the same as a kg-m/s2, so multiplying the mass in kilograms times the acceleration due to gravity would give an answer in newtons. It all made sense to me, but I am sure that the students just went along with me to get the right answer.