4. A toy train engine rest motionless on a track One student begins pushing the engine to the right with a force of 2 N. At the same time, another student begins pushing the engine to the left
with a force of 5 N. What is the net force acting on the train and which direction will it move?
Draw it out below! *Use a box for the train and arrows for force

What does the process of natural selection involve

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.

Type the letter that represents the correct location for each particle type below.