Abox is lowered using a rope. if the acceleration of the box, is 2.5 m/s2 (downward) and the tension in the rope is 31 n, what is the mass of the box (in kg)?

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.