A 4.0 kg mass is 1.0 m away from a 7.0 kg mass. What is the gravitational force between the two masses? (Remember to use the gravitational constant, G = 6.67 x 10-11 N x m2/ kg2, in your calculation.) 6.67 x 1010N
1.9 x 10-9N
3.8 N
6.67 x 10-11 N

Two objects of different mass start from rest, are pulled by the same magnitude net force, and are moved through the same distance. the work done on object 1 is 900 j. after the force has pulled each object, object 1 moves twice as fast as object 2. how much work is done on object 2?

Aparticle of mass m is placed in a one-dimensional box of length l. the box is so small that the particle’s motion is relativistic, so that e p2/2m is not valid. (a) derive an expression for the energy levels of the particle using the relativistic energy–momentum relation and the quantization of momentum that derives from connement. (b) if the particle is an electron in a box of length l 1.00 1012 m, nd its lowest possible kinetic energy. by what percent is the nonrelativistic formula for the energy in error?

Acar of mass 800kg is moving at a speed of 2.2m/s.