The positive muon (? +), an unstable particle, lives on average 2.20×10? 6s (measured in its own frame of reference) before decaying. a. if such a particle is moving, with respect to the laboratory, with a speed of 0.910 c , what average lifetime is measured in the laboratory? b. what average distance, measured in the laboratory, does the particle move before decaying?

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?