Some bacteria are propelled by biological motors that spin hairlike flagella. A typical bacterial motor turning at a constant angular velocity has a radius of 1.5 × 10-8 m, and a tangential speed at the rim of 2.3 × 10-5 m/s. (a) What is the angular speed (the magnitude of the...
01 Apr 2020Suppose the kick in Example 3-5 is attempted 36.0m from the goalposts, whose crossbar is 3.00m above the ground. If the football is directed correctly between the goalposts, will it pass over the bar and be a field goal? Show why or why not.
01 Apr 2020Suppose you pour water into a container until it reaches a depth of 14 cm. Next, you carefully pour in a 7.5-cm thickness of olive oil so that it floats on top of the water. What is the pressure at the bottom of the container?
01 Apr 2020Tenisha Gist cuts brass plates for an engraving job. From a sheet of brass, three pieces 4 4/5 inches wide and two pieces 7 3/8 inches wide are cut. What is the smallest sheet of brass required to cut all five plates? Tenisha Gist cuts brass plates for an engraving job From
01 Apr 2020The average density of the Earth is 5.52 g/cm3. Assuming this is a uniform density, compute the value of G.
01 Apr 2020The average number of days construction workers miss per year The average number of days construction workers miss per year is 11. The standard deviation is 2.3. The average number of days factory workers miss per year is 8 with a standard deviation of 1.8. Which class is more v...
01 Apr 2020The citizens of Paris were terrified during World War I when they were suddenly bombarded with shells fired from a long-range gun known as Big Bertha. The barrel of the gun was 36.6 m long and it had a muzzle speed of 1.46 km/s. When the gun’s angle of elevation was set to 55°, w...
01 Apr 2020The distance between atoms in a crystal of NaCl is 0.28 nm. The crystal is being studied in a neutron diffraction experiment. At what speed must the neutrons be moving so that their de Broglie wavelength is 0.28 nm?
01 Apr 2020The fundamental wavelength for standing sound waves in an empty pop bottle is 0.88 m. (a) What is the length of the bottle? (b) What is the frequency of the third harmonic of this bottle?
01 Apr 2020The hang time of a basketball player who jumps a vertical distance of 2 feet (0.6 m) is about 2/3 second. What will be the hang time if the player reaches the same height while jumping 4 feet (1.2 m) horizontally?
01 Apr 2020The inside of a cell membrane is at a potential of 90.0 mV lower than the outside. How much work does the electric field do when a sodium ion (Na) with a charge of e moves through the membrane from outside to inside?
01 Apr 2020The lowest note on a piano is A, four octaves below the A given in Table 14-3. The highest note on a piano is C, four octaves above middle C. Find the frequencies and wavelengths (in air) of these notes. In table 14-3 Note _________________________________ Frequency (Hz) ...
01 Apr 2020The magnetic field in a cyclotron is 0.360 T. The dees have radius 82.0 cm. What maximum speed can a proton achieve in this cyclotron?
01 Apr 2020The pilot of an airplane wishes to fly due north, but there is a 65-km/h wind blowing toward the east. (a) In what direction relative to north should the pilot head her plane if its speed relative to the air is 340 km/h? (b) Draw a vector diagram that illustrates your resul...
01 Apr 2020The position of a mass oscillating on a spring is given by x = (7.8 cm) cos[2πt/(0.68 s)]. (a) What is the frequency of this motion? (b) When is the mass first at the position x = -7.8 cm?
01 Apr 2020The wheels of a skateboard roll without slipping as it accelerates at 0.35 m/s2 down an 85-m-long hill. If the skateboarder travels at 1.8 m/s at the top of the hill, what is the average angular speed of the 2.6-cm-radius wheels during the entire trip down the hill?
01 Apr 2020The x vector component of a displacement vector r→ has a magnitude of 125 m and points along the negative x-axis. The y vector component has a magnitude of 184 m and points along the negative y-axis. Find the magnitude and direction of r→ specify the direction with respect to the...
01 Apr 2020Two bullets are fired at the same time with the same kinetic energy. If one bullet has twice the mass of the other, which has the greater speed and by what factor? Which can do the most work?
01 Apr 2020Two canal workers pull a barge along the narrow waterway at a constant speed. One worker pulls with a force of 105 N at an angle of 28° with respect to the forward motion of the barge and the other worker, on the opposite towpath, pulls at an angle of 38° relative to the barge mo...
01 Apr 2020Two cylindrical metal rods-one copper, the other lead-are connected in parallel with a temperature of 21.0°C at one end and 112°C at the other end. Both rods are 0.650 m in length, and the lead rod is 2.76 cm in diameter. If the combined rate of heat flow through the two rods i...
01 Apr 2020Two engines operate between the same two temperatures of 750 K and 350 K, and have the same rate of heat input. One of the engines is a reversible engine with a power output of 2.3 × 104 W. The second engine has an efficiency of 42%. What is the power output of the second engine?
01 Apr 2020Two ice skaters have masses m1 and m2 and are initially stationary. Their skates are identical. They push against one another, as in Figure 7.9, and move in opposite directions with different speeds. While they are pushing against each other, any kinetic frictional forces actin...
01 Apr 2020Two ice skaters not paying attention to collide in a completely inelastic collision. Prior to the collision, skater 1, with a mass of 60 kg, has a velocity of east-ward and moves at a right angle to skater 2, who has a mass of 75 kg and a velocity of southward. What is the veloci...
01 Apr 2020Two identical cars, each traveling at 16 m/s, slam into a concrete wall and come to rest. In-car A the airbag does not deploy and the driver hits the steering wheel; in car B the driver contacts the deployed airbag. (a) Is the impulse delivered by the steering wheel to driver ...
01 Apr 2020Two musicians are comparing their clarinets. The first clarinet produces a tone that is known to be 466 Hz. When the two clarinets play together they produce eight beats every 3.00 seconds. If the second clarinet produces a higher-pitched tone than the first clarinet, what is the...
01 Apr 2020Two skaters with masses of 65 kg and 45 kg, respectively, stand 8.0 m apart, each holding one end of a piece of rope. (a) If they pull themselves along the rope until they meet, how far does each skater travel? (Neglect friction.) (b) If only the 45-kg skater pulls along th...
01 Apr 2020Two waves with identical frequency but different amplitudes A1 = 6.0 cm and A2 = 3.0 cm, occupy the same region of space (i.e., are superimposed). (a) At what phase difference will the resulting wave have the highest intensity? What is the amplitude of the resulting wave in th...
01 Apr 2020Using the scale 1.0 cm = 50 km, find the length of the vector that represents each displacement. 1. Displacement 100 km east length = _____ cm 2. Displacement 125 km south length = _____ cm 3. Displacement 140 km at 45° east of south length = _____ cm 4. Displacement 260 km a...
01 Apr 2020Vector A→ points along the y-axis and has a magnitude of 100.0 units. Vector B→ points at an angle of 60.00 above the x-axis and has a magnitude of 200.0 units. Vector C→ points along the x-axis and has a magnitude of 150.0 units. Which vector has? (a) The largest x component an...
01 Apr 2020What is the frequency of the microwaves in a microwave oven? The wavelength is 12 cm.
01 Apr 2020What is the maximum electric energy density possible in dry air without dielectric breakdown occurring?
01 Apr 2020When 1310 J of heat are added to one mole of an ideal monatomic gas, its temperature increases from 272 K to 276 K. Find the work done by the gas during this process.
01 Apr 2020When at rest, your heart pumps blood at the rate of 5.00 liters per minute (L/min). What are the volume and mass of blood pumped by your heart in one day?
01 Apr 2020When the author attended high school some 60 years ago, his teacher showed a piece of uranium ore and measured its radioactivity with a Geiger counter. Would that reading for the same piece of ore be different today?
01 Apr 2020When water freezes, it expands by about 9.00%. What pressure increase would occur inside your automobile engine block if the water in it froze? (The bulk modulus of ice is 2.00 – 109 N/m2.)
01 Apr 2020William Tell is said to have shot an apple off his son’s head with an arrow. If the arrow was shot with an initial speed of 55 m/s and the boy was 15 m away, at what launch angle did Bill aim the arrow? (Assume that the arrow and apple are initially at the same height above the g...
01 Apr 2020Would the springs inside a bathroom scale be more compressed or less compressed if you weighed yourself in an elevator that was moving upward at constant velocity? Downward at constant velocity?
01 Apr 2020You are on the street trying to hit a friend in his dorm window with a water balloon. He has a similar idea and is aiming at you with his water balloon. You aim straight at each other and throw at the same instant. Do the water balloons hit each other? Explain why or why not.
01 Apr 2020You have a choice of borrowing money from a finance company at 24 percent compounded monthly or borrowing money from a bank at 26 percent compounded annually. Which alternative is the most attractive?You have a choice of borrowing money from a finance
01 Apr 2020You want to build a cyclotron to accelerate protons to a speed of 3.0 × 107 m/s. The largest magnetic field strength you can attain is 1.5 T. What must be the minimum radius of the dees in your cyclotron? Show how your answer comes from Newton’s second law.
01 Apr 2020The spring of modulusk = 640 N/m is stretched a distanced = 68 mm when the mechanism is in the position shown. (a) Calculate the forcePmin required to initiate rotation about the hinge axisBC, and determine the corresponding magnitudes of the bearing forces which are perpendicul...
01 Apr 2020Calculate the theoretical pH of one of your buffers at0ºC(TRIS). Assume that room temperature is 22ºC. If none of yourbuffers is listed on the table of changing pKa with temperature, dothe problem for TRIS at pH 8.0. pKa = 8.3. There are other answersposted but they are wrong. ch...
01 Apr 2020When a certain liquid freezes at -3.65°C its density changes from 0.789 g cm-3 to 0.801 g cm-3 Its enthalpy of fusion is 8.68 k] mol-1. Estimate the freezing point of the liquid at 100 MPa.
01 Apr 2020What is the frequency, in hertz, that corresponds to each of the following periods? (a) 0.10 s (b) 5 s (c) 1/60 s
01 Apr 2020A vessel of volume 22.4 dm ‘ contains 1.5 mol H2 and 2.5 mol N2 at 273.15 K. Calculate (a) The mole fractions of each component, (b) Their partial pressures, and (c) Their total pressure.
01 Apr 2020Use Coulomb’s law, F = kQ1Q2/d2, to calculate the electric force on an electron (Q = – 1.6 × 10-10 C) exerted by a single proton if the particles are 0.53 × 10-10 m apart. The constant k in Coulomb’s law is 9.0 × 109 N ∙ m2/C2. (The unit abbreviated N is the newton, the SI unit o...
01 Apr 2020Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. The frequency of the waves emitted by each speaker is 172 Hz. You are 8.00 m from A. What is the closest you can be to B and be at a point of destructive interference?
01 Apr 2020Two electrically charged pith balls, each having mass M, are suspended from light threads of equal length. Determine the resultant horizontal force of repulsion, F, acting on each ball if the measured distance between them is r. Given: M = 0.2 gm r = 200 mm l = 150 mm d = 50...
01 Apr 2020The temperature of a silver bar rises by 10.0°C when it absorbs 1.23 kJ of energy by heat. The mass of the bar is 525 g. Determine the specific heat of silver.
01 Apr 2020
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