12. An 8 g bullet is fired from a rifle. The bullet passes through a 10 cm plank. This reduces the bullet's velocity from 400 m. s-1 west to 300 m. s-1 west.
a) Calculate the bullet's initial momentum.
b) Calculate the bullet's final momentum.
c) Calculate the bullet's change in momentum.
d) Draw a labelled vector diagram to illustrate the bullet's initial, final and
change in momentum vectors.

According to the tide table below what time of day will the highest tide occur?

The particle in a two-dimensional well is a useful model for the motion of electrons around the indole ring (3), the conjugated cycle found in the side chain of tryptophan. we may regard indole as a rectangle with sides of length 280 pm and 450 pm, with 10 electrons in the conjugated p system. as in case study 9.1, we assume that in the ground state of the molecule each quantized level is occupied by two electrons. (a) calculate the energy of an electron in the highest occupied level. (b) calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels. 9.27 electrons around the porphine ring (4), the conjugated macrocycle that forms the structural basis of the heme group and the chlorophylls. we may treat the group as a circular ring of radius 440 pm, with 20 electrons in the conjugated system moving along the perimeter of the ring. as in exercise 9.26, assume that in the ground state of the molecule quantized each level is occupied by two electrons. (a) calculate the energy and angular momentum of an electron in the highest occupied level. (b) calculate the frequency of radiation that can induce a transition between the highest occupied and lowest unoccupied levels.

Determine el momento angular de un rueda de 3000g moviendose a 10m/s con un radio de giro de 400cm