A 2.5 kg block is sitting on a flat, frictionless surface. It has 3, horizontal ropes attached to it at different points. (note: All directions stated are with an overhead view, i. e., you are looking down on the block.) Rope #1 has a tension of 90 N in the direction of 35° north of east. Rope #2 is being pulled in the direction of 270° with a force of 85 N. The third rope’s tension is 111 N at 41.5° west of north. a.) What is the net force on the block?
b.) What is the acceleration of the block?

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?

Work out sian speed for the first 30 minutes of her journey. give your answer in km/h.

Waves that cause the most damage during an earthquake are a. surface waves c. s waves b. p waves d. ocean waves