A rigid, uniform, horizontal bar of mass m1 and length L is supported by two identical massless strings. (Figure 1)Both strings are vertical. String A is attached at a distance d Throughout this problem positive torque is that which spins an object counterclockwise. Use g for the magnitude of the acceleration due to gravity.

A)
Find TA, the tension in string A.

Express the tension in string A in terms of g, m1, L, d, m2, and x.

B)
Find TB, the magnitude of the tension in string B.

Express the magnitude of the tension in string B in terms of TA, m1, m2, and

C)
If the mass of the block is too large and the block is too close to the left end of the bar (near string B) then the horizontal bar may become unstable (i. e., the bar may no longer remain horizontal).

What is the smallest possible value of x such that the bar remains stable (call it xcritical)?

Express your answer for xcritical in terms of m1, m2, d, and L.

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.

The earth is constantly spinning on its axis, like you might spin a basketball on your finger. it is this spinning of the earth that causes

Positrons are spontaneously emitted from the nuclei of