Suppose a rock is sitting on a table. Which statement below best describes the forces involved? a. No forces are acting on the rock or table because neither is moving.
b. The rock is exerting a downward force on the table, but the table is not exerting a force.
c. The table exerting an upward force on the rock, but the rock is not exerting a force.
d. The rock is exerting a downward force on the table, and the table is exerting an upward force
on the rock.

Research the neutrino using the internet and report your findings. in a nuclear decay, the nucleus of an atom splits apart. larger particles can be detected and their masses and velocities can be recorded. explain how the existence and properties of the neutrino could be predicted using the conservation laws.

A1200 kg car traveling north at 10 m/s is rear-ended by a 2000 kg truck traveling at 30 m/s. what is the total momentum before and after the collision?

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?