Jenny is sitting on a sled on the side of a hill inclined at 15°. what force is required to keep the sled from sliding down the
hill if the combined weight of jenny and the sled is 90 pounds?
[got deleted from mathematics when it's for pre-calculus, if this isn't physics or math where should i ask my question? ]

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?