1. An object is dropped from a height of 100 m at the same time that a similar object is fired horizontally from the same height. Disregarding the effects of the atmosphere, do they hit at the same time? WHY? 2. Describe the horizontal and vertical velocity and acceleration components of a projectile fired horizontally from the top of a building.

3. Suppose that an airplane flying 60 m/s, at a height of 300m, dropped a sack of flour. How far from the point of release would the sack have traveled when it struck the ground? (Hint: Find the time it takes to hit the ground first)

4. A book is pushed with an initial horizontal velocity of 5.0 m/s off the top of a desk. What is the initial vertical velocity of the book?

5. A ball is thrown horizontally from the top of a building with an initial velocity of 15 m/s. At the same instant, a second ball is dropped from the top of the building. The two balls have the same:

1. paths they fall
2. final velocity as they reach the ground
3. initial horizontal velocity
4. initial vertical velocity

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.

In a system, when potential energy decreases, then entropy also decreases. true false

The average density of the planet uranus is 1.27 103 kg/m3. the ratio of the mass of neptune to that of uranus is 1.19. the ratio of the radius of neptune to that of uranus is 0.969. find the average density of neptune.