Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ===== Pre-lecture:Local Gravity ===== * In the absence of other interactions, we observe that things fall at a rate of 9.8 m/s/s. There's some flexibility in this number, but it's pretty close to this value everywhere on earth. * It's special we call it 'g' * This empirical fact means that the momentum principle predicts the force this object experiences is equal to mg. * This also turns out to be true. The force due to the Earth on any system near the surface of the earth is given by m_sys*g. * For example, tossing a puppy? m_puppy*g is the force of gravity on the puppy it is directed "downward" towards Earth's surface, so as a vector we often say is <0,-mg,0>. * When we can neglect other interactions our constant force equations give us a set of equations that govern the motion of systems experience local gravity. * Use CF equations to produce kinematic equations. * These are often useful when the only important interaction is the gravitational force. temp/prelec/cf-g.txt Last modified: 2014/07/24 02:09by caballero