Depressing the brake pedal in a carpushes on a piston with cross-sectional area 3.0cm2.the
piston applies pressure to the brake fluid, which is connected totwo pistons, each with area 12.0
cm2. each of these pistonspresses a brake pad against one side of a rotor attached to one ofthe
rotating wheels (the figure below )when the force applied by the brake pedal to thesmall
piston is 7.5 n, what is the normalforce applied to each side of the rotor? (b) if the coefficientof
kinetic friction between a brake pad andthe rotor is 0.80 and each pad is (on average) 12 cmfrom
the rotation axis of the rotor, what isthe torque on the rotor due to the two pads?

Chapter 23, problem 075 the figure shows a geiger counter, a device used to detect ionizing radiation (radiation that causes ionization of atoms). the counter consists of a thin, positively charged central wire surrounded by a concentric, circular, conducting cylindrical shell with an equal negative charge. thus, a strong radial electric field is set up inside the shell. the shell contains a low-pressure inert gas. a particle of radiation entering the device through the shell wall ionizes a few of the gas atoms. the resulting free electrons (e) are drawn to the positive wire. however, the electric field is so intense that, between collisions with gas atoms, the free electrons gain energy sufficient to ionize these atoms also. more free electrons are thereby created, and the process is repeated until the electrons reach the wire. the resulting "avalanche" of electrons is collected by the wire, generating a signal that is used to record the passage of the original particle of radiation. suppose the radius of the central wire is 24 âµm, the inner radius of the shell 2.3 cm, and the length of the shell 14 cm. if the electric field at the shell's inner wall is 2.8 ă— 104 n/c, what is the total positive charge on the central wire?

The system is released from rest with the cable taut, and the homogeneous cylinder does not slip on the rough incline. determine the angular acceleration of the cylinder and the minimum coeffi cient s of friction for which the cylinder will not slip.

Apair of 10μf capacitors in a high-power laser are charged to 1.7 kv. a. what charge is stored in each capacitor? b. how much energy is stored in each capacitor?