An electron collides elastically with a stationary hydrogen atom. the mass of the hydrogen atom is 1837 times that of the electron. assume all motion is along a straight line. what is the ratio of the kinetic energy of the hydrogen atom after the collision to that of the of the electron before the collision?

Currents in dc transmission lines can be 100 a or higher. some people are concerned that the electromagnetic fields from such lines near their homes could pose health dangers. for a line that has current 150 a and a height of 8.0 m above the ground, what magnetic field does the line produce at ground level? express your answer in teslas and as a percentage of the earth’s magnetic field, which is 0.50 g. is this value cause for worry?