A point charge of +7.45 pC (7.45 × 10-12 C) is fixed at the origin. What is the electric field produced by this charge at point P, which is on the x-axis, 9.83 mm from the origin?

Ahole in the ground in the shape of an inverted cone is 14 meters deep and has radius at the top of 11 meters. the cone is filled to the top with sawdust. the density of the sawdust depends upon the depth, x, following the formula ρ ( x ) = 2.5 + 1.2 e − 0.7 x kg/m3. find the total mass of sawdust in the conical hole.