You push a 2.3 kg block against a horizontal spring, compressing the spring by 17 cm. then you release the block, and the spring sends it sliding across a tabletop. it stops 88 cm from where you released it. the spring constant is 200 n/m. what is the block–table coefficient of kinetic friction?

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?