a rocket is continuously firing its engines as it accelerates away from earth. for the first kilometer of its ascent, the mass of fuel ejected is small compared to the mass of the rocket. for this distance, which of the following indicates the changes, if any, in the kinetic energy of the rocket, the gravitational potential energy of the earth-rocket system, and the mechanical energy of the earth-rocket system?

Two 1.20-m nonconducting wires meet at a right angle. one segment carries + 2.50 µc of charge distributed uniformly along its length, and the other carries - 2.50 µc distributed uniformly along it, as shown in fig. 21.50. ( a. find the magnitude and direction of the electric field these wires produce at point p, which is 60.0 cm from each wire. ( b. if an electron is released at p, what are the magnitude and direction of the net force that these wires exert on it?