The hour and minute hands of the clock in the famous parliament clock tower in london are 1.7 m and 3.4 m long and have masses of 89 kg and 60 kg, respectively calculate the magnitude of the torque around the center of the clock due to the weight of these hands indicating 3 h and 1 min; i. e., 3: 1 o’clock. assume the clock hands can be modeled as uniform thin rods and at 3: 00 o’clock, the hour hand is precisely 90◦ from the vertical. the acceleration of gravity is 9.81 m/s 2 . answer in units of n · m

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?

If the ama of the inclined plane below is 2, calculate the ima and efficiency. ima = efficiency =

A20 cm long spring is attached to a wall. the spring stretches to a length of 22 cm when you pull on it with a force of 100 n. what is the spring constant