OC userin Physics·4 Dec 20175.30 - Some sliding rocks approach the base of a hill with a speed of 12 m/s. The hill rises at 36° above the horizontal and has coefficients of kinetic friction and static friction of 0.45 and 0.65, respectively, with these rocks. (a) Find the acceleration of the rocks as they slide up the hill. (b) Once a rock reaches its highest point, will it stay there or slide down the hill? If it stays, show why. If it slides, find its acceleration on the way down.
OC userin Physics·2 Dec 20179.18 . In a charming 19th-century hotel, an old-style elevator is connected Figure E9.18 to a counterweight by a cable that passes over a rotating disk 2.50 m in diameter (Fig. E9.18). The elevator is raised and lowered by turning the Disk disk, and the cable does not slip on the rim of the disk but turns with it. (a) At how many rpm must the disk turn to raise the elevator at 25.0 cm/s? (b) To start the elevator moving, it must be accelerated at 8. What must be the angular acceleration of the disk, in rad/s"? (c) Through whatCounterweight angle (in radians and degrees) has the disk turned when it has raised the elevator 3.25 m between floors? Elevator
OC userin Physics·3 Dec 20171.81 .. Vector A has magnitude 12.0 m, and vector B has mag- nitude 16.0 m. The scalar product A B is 112.0 m². What is the magnitude of the vector product between these two vectors?
OC userin Physics·30 Nov 201755. Use data from Appendix IIB to calculate ASxn for each of the reactions. In each case, try to rationalize the sign of ASx a. C2H4(3) + H2(g) →→ CH68) b. C(s) + H2O(g) — CO(g) + H2(g) c. CO(g) + H2O(g) — H2() + CO2(8) d. 2 H,S(g) + 3 02(g) 2 H2O(l) + 2 SO2()
OC userin Chemistry·1 Dec 20171. What is Brownian motion? How is it related to the development of the idea that matter is particulate?
OC userin Physics·2 Dec 201733. How is the amount of current flowing through an electrolytic cell related to the amount of product produced in the redox reaction?
OC userin Chemistry·30 Nov 2017109. Consider the stack of pennies in the previous problem. How much money in dollars) would this represent? If this money were equally distributed among the world's population of 7.0 billion people, how much would each person receive? Would each per son be a millionaire? A billionaire? A trillionaire?
OC userin Chemistry·2 Dec 201793. Determine whether the two structures are isomers or the same molecule drawn in two different ways. a. CH3-CH=C0–CH, | CHG-0–0–CH3–CH, C. CH3-HC-CH-CH3 CH3 CH3 CH3 CHI-HC-CH=CH, CH3
OC userin Physics·2 Dec 201725.25. A copper transmission cable 100 km long and 10.0 cm in diameter carries a current of 125 A. (a) What is the potential drop across the cable? (b) How much electrical energy is dissipated as thermal energy every hour?
OC userin Chemistry·29 Nov 201742. Which statements are inconsistent with Rutherford's nuclear theory as it was originally stated? Why? a. Since electrons are smaller than protons, and since a hydro- gen atom contains only one proton and one electron, it must follow that the volume of a hydrogen atom is mostly due to the proton. b. A nitrogen atom has seven protons in its nucleus and seven electrons outside of its nucleus. c. A phosphorus atom has 15 protons in its nucleus and 150 electrons outside of its nucleus. d. The majority of the mass of a fluorine atom is due to its nine electrons.
OC userin Chemistry·28 Nov 2017110. Which is more efficient, a butane lighter or an electric lighter (such as the ones traditionally found on the dashboard of auto- mobiles)? Explain.
OC userin Chemistry·28 Nov 201717. In a reaction mechanism, what is an elementary step? Write down the three most common elementary steps and the corre- sponding rate law for each one.
OC userin Physics·28 Nov 2017103. Nuclei with the same number of neutrons but different mass numbers are called isotones. Write the symbols of four isotones of 236 Th.
OC userin Chemistry·29 Nov 2017Q6. A reaction has AHpx = -255 kJ and ASix = 211J/K. Calculate AG xn at 55 °C. a) 11.9 X 10 kJ b) 69.5 X 10 kJ c) -267 kJ d) -324 kJ