OC userin Physics·19 Dec 201714.39. A thrill-seeking cat with mass 4.00 kg is attached by a harness to an ideal spring of negligible mass and oscillates vertically in SHM. The amplitude is 0.050 m, and at the highest point of the motion the spring has its natural unstretched length. Calculate the elastic potential energy of the spring (take it to be zero for the unstretched spring), the kinetic energy of the cat, the gravitational potential energy of the system relative to the lowest point of the motion, and the sum of these three energies when the cat is (a) at its highest point; (b) at its lowest point; (c) at its equilibrium position.
OC userin Physics·18 Dec 201772. Magnesium has three naturally occurring isotopes with the fol- lowing masses and natural abundances: Isotope Mg-24 Mg-25 Mg-26 Mass (amu) 23.9850 24.9858 25.9826 Abundance (%) 78.99 10.00 11.01 Sketch the mass spectrum of magnesium.
OC userin Physics·19 Dec 201725.3.A 5.00-A current runs through a 12-gauge copper wire (diameter 2.05 mm) and through a light bulb. Copper has 8.5 X 10 free electrons per cubic meter. (a) How many electrons pass through the light bulb each second? (b) What is the current density in the wire? (c) At what speed does a typical electron pass by any given point in the wire? (d) If you were to use wire of twice the diameter, which of the above answers would change? Would they increase or decrease?
OC userin Physics·18 Dec 20171.48 . For the two vectors A and B in Fig. E1.39, find (a) the scalar product A B; (b) the magnitude and direction of the vector product AXB.
OC userin Physics·18 Dec 201789. Calculate the mass, in grams, of each sample a. 1.1 x 102 gold atoms b. 2.82 x 10” helium atoms c. 1.8 x 1023 lead atoms d. 7.9 x 1021 uranium atoms
OC userin Physics·18 Dec 2017Q8.3 When rain falls from the sky, what happens to its momen- tum as it hits the ground? Is your answer also valid for Newton's famous apple?
OC userin Physics·16 Dec 201739. Use the Henderson-Hasselbalch equation to calculate the pH of each solution. a. a solution that is 0.135 M in HClO and 0.155 M in KCIO b. a solution that contains 1.05% C2H5NH2 by mass and 1.10% C2H5NH3Br by mass c. a solution that contains 10.0 g of HC2H2O2 and 10.0 g of NaC,H,O, in 150.0 mL of solution
OC userin Physics·15 Dec 201738. Use the Henderson-Hasselbalch equation to calculate the pH of each solution in Problem 30.
OC userin Physics·17 Dec 20175.21 .. CP BIO Force During a Jump. When jumping straight up from a crouched position, an average person can reach a max- imum height of about 60 cm. During the jump, the person's body from the knees up typically rises a distance of around 50 cm. To keep the calculations simple and yet get a reasonable result, assume that the entire body rises this much during the jump. (a) With what initial speed does the person leave the ground to reach a height of 60 cm? (b) Draw a free-body diagram of the per- son during the jump. (c) In terms of this jumper's weight w, what force does the ground exert on him or her during the jump?
OC userin Physics·15 Dec 201743. Calculate the change in Gibbs free energy for each of the sets of AHxn, ASxn, and T given in Problem 41. Predict whether or not each reaction is spontaneous at the temperature indicated. (Assume that all reactants and products are in their standard states.)
OC userin Physics·14 Dec 2017Q2.6 Under what conditions does the magnitude of the average velocity equal the average speed?
OC userin Physics·12 Dec 20179.40 .. You need to design an industrial turntable that is 60.0 cm in diameter and has a kinetic energy of 0.250 J when turning at 45.0 rpm (rev/min). (a) What must be the moment of inertia of the turntable about the rotation axis? (b) If your workshop makes this turntable in the shape of a uniform solid disk, what must be its mass?
OC userin Physics·11 Dec 20179.82 - BIO The Kinetic Energy of Running. Using Problem 9.81 as a guide, apply it to a person running at 12 km/h, with his arms and legs each swinging through 30° in s. As before, assume that the arms and legs are kept straight.
OC userin Physics·13 Dec 201724.3. A parallel-plate air capacitor of capacitance 245 pF has a charge of magnitude 0.148 C on each plate. The plates are 0.328 mm apart. (a) What is the potential difference between the plates? (b) What is the area of each plate? (©) What is the electric- field magnitude between the plates? (d) What is the surface charge density on each plate?
OC userin Physics·11 Dec 2017Q1.25 (a) If A B = 0, does it necessarily follow that A = 0 or B = 0? Explain. (b) If AXB = 0, does it necessarily follow that A = 0 or B = 0? Explain.