In an asymmetric colliding beam experiment, a beam of electrons e" strike a beam of positrons e+ traveling in the opposite direction. suppose that the electrons are moving in the positive x-direction and the positrons are moving in the negative x-direction. denoting the position of an electron by xe, the position of a positron by xp, the position of the center of mass of an electron positron pair by x, and the mass of an electron or a positron by m, the position of the center of mass is given by the equation the speed of the positrons is 0.2c. calculate the velocity of the the collision between an electron and a positron produces (a) suppose the speed of the electrons is 0.95c and center of mass of an electron-positron pair. (b) suppose that a particle at rest in the center of mass system, which decays in 2.0 x 10-8 s. what will the lifetime of the be in the laboratory frame of reference? the asymmetric colliding beam technique has been used in an experiment performed by scientists at cornell university. the time-dilation effect makes the experiment possible. 0 90e toward the star sirius, which is 8.6 light years away

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 human body stores chemical energy from digested food. some of the chemical energy is converted into mechanical energy when the body moves. which statement best supported by this information

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is