1) Two crates of mass 20.0 kg and 35.0 kg are pushed up along an incline of 33.0 degrees by a force of 550 N. Coefficients of kinetic friction are 0.25 and 0.37 respectively for the two crates. (a) Draw force diagrams for each of the crates. (b) Calculate the acceleration of the two crates. (c) Calculate the contact force between the two crates. (d) What would be the contact force if the two crates are reversed?

An uncharged nonconductive hollow sphere of radius 18.0 cm surrounds a 12.0 µc charge located at the origin of a cartesian coordinate system. a drill with a radius of 1.00 mm is aligned along the z axis, and a hole is drilled in the sphere. calculate the electric flux through the hole.

Two identical 82 mg dust particles very far apart (pee 0) are moving directly toward each other at a speed of 3698 m/s. the charge on each is-719 ? c. determine how close they will get to each other. let k = 9x109 n-m2/c2 & ignore gravity.

The membrane surrounding a living cell consists of an inner and an outer wall that are separated by a small space. assume that the membrane acts like a parallel plate capacitor in which the effective charge density on the inner and outer walls has a magnitude of 7.0 × 10-6 c/m2. (a) what is the magnitude of the electric field within the cell membrane? (b) find the magnitude of the electric force that would be exerted on a potassium ion (k+; charge = +e) placed inside the membrane.