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Condition |
free/or 0.5$ |
| 55103 | A basement room containing radon gas (t1/2 = 3.82days) is sealed to be airtight.
(a) If 7.50 x 1010 radon atoms are trapped in the room, estimate how many radon atoms remain in the room after one week.
(b) Radon undergoes alpha decay. After 30 days, is the number of its daughter nuclei equal to, or less than, the number of radon parents that have decayed? Explain your reasoning. |
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| 55104 | A baseball player pops a pitch straight up. The ball (mass 200 g) was traveling horizontally at 35.0 m/s just before contact with the bat, and 20.0 m/s just after contact. Determine the direction and magnitude of the impulse delivered to the ball by the bat. |
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| 55105 | A baseball player hits a home run into the right field upper deck. The ball lands in a row that is 135 m horizontally from home plate and 25.0 m above the playing field. An avid fan measures its time of flight to be 4.10 s.
(a) Determine the ball’s average velocity components.
(b) Determine the magnitude and angle of its average velocity.
(c) Explain why you cannot determine its aver-age speed from the data given. |
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| 55106 | A bar magnet is dropped through a coil of wire as shown in Fig. 20.29.
(a) Describe what is observed on the galvanometer by sketching a graph of induced emf versus t.
(b) Does the magnet fall freely? Explain. |
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| 55107 | A ballistic pendulum is a device used to measure the velocity of a projectile— for example, the muzzle velocity of a rifle bullet. The projectile is shot horizontally into, and becomes embedded in, the bob of a pendulum, as illustrated in Fig. 6.35. The pendulum swings upward to some height h, which is measured. The masses of the block and the bullet are known. Using the laws of momentum and energy, show that the initial velocity of the projectile is given by vo = [(m + M/m)]√2gh. |
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| 55108 | A ball with a horizontal speed of rolls off a bench 2.0 m high.
(a) How long will the ball take to reach the floor?
(b) How far from a point on the floor directly below the edge of the bench will the ball land? |
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| 55109 | A ball rolls horizontally with a speed of 7.6 m/s off the edge of a tall platform. If the ball lands 8.7 m from the point on the ground directly below the edge of the plat-form, what is the height of the platform? |
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| 55110 | A ball rolls down a roof that makes an angle of to the horizontal (Fig. 3.37). It rolls off the edge with a speed of 5.00 m/s. The distance to the ground from that point is two stories or 7.00 m.
(a) How long is the ball in the air?
(b) How far from the base of the house does it land?
(c) What is its speed just before landing? |
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| 55111 | A ball rolls at a constant velocity of 1.50 m/s at an angle of 45o below the in the fourth quadrant. If we take the ball to be at the origin at t = 0 what are its coordinates (x, y) 1.65 s later? |
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| 55112 | A ball rolling on a table has a velocity with rectangular components vx = 0.60 m/s and vy = 0.80 m/s. What is the displacement of the ball in an interval of 2.5 s? |
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| 55113 | A ball of mass 200 g is released from rest at a height of 2.00 m above the floor and it rebounds straight up to a height of 0.900 m.
(a) Determine the ball’s change in momentum due to its contact with the floor.
(b) If the contact time with the floor was 0.0950 s, what was the average force the floor exerted on the ball, and in what direction? |
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| 55114 | A ball is projected horizontally with an initial speed of 5.0 m/s. Find its
(a) Position and
(b) Velocity at t = 25s. |
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| 55115 | A bag of potatoes with weight 39.2 N is suspended from a string that exerts a force of 46.8 N. If the bag s acceleration is upward at 1.90 m/s2, what is the mass of the potatoes? |
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| 55116 | (a) At what position is the speed of a mass in a mass–spring system maximum: (1) x = 0, (2) x = – A, or (3) x = + A? Why?
(b) If m = 0.250 kg, k = 1000 N/m, and A = 0.10m for such a system, what is the mass’s maximum speed? |
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| 55117 | (a) At what position is the magnitude of the force on a mass in a mass–spring system minimum: (1) x = 0, (2) x = – A, or (3) x = + A? Why?
(b) If m = 0.500 kg, k = 150 N/m, and A = 0.150 m, what are the magnitude of the force on the mass and the acceleration of the mass at, x = 0.050 m, and 0.150 m? |
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| 55118 | (a) At one-third the original distance from a positive point charge, by what factor is the electric potential changed: (1) 1/3, (2) 3, (3) 1/9, or (4) 9? Why?
(b) How far from a +1.0-μC charge is a point with an electric potential value of 10 kV?
(c) How much of a change in potential would occur if the point were moved to three times that distance? |
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| 55119 | (a) Assuming the range of the nuclear force to be 1.0 x 10-15m, predict the mass (in kilograms) of the exchange particle related to this force.
(b) Convert the answer into the particle’s rest energy (in MeV) and identify it. |
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| 55120 | (a) As you start in the very middle of Fig. 19.3b and move horizontally to the right, what happens to the magnetic field spacing as indicated by the iron filing pat-tern? What does this imply in terms of the magnetic field strength?
(b) What is the direction of the magnetic field in this region of the figure? Can you tell the direction from the iron filing pattern alone? Explain. |
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| 55121 | (a) As a weightlifter lifts a barbell from the floor in the “clean” procedure (Fig. 5.25a), has he done work? Why or why not?
(b) In raising the barbell above his head in the “jerk” procedure, is he doing work? Explain.
(c) In holding the barbell above his head (Fig. 5.25b), is he doing more work, less work, or the same amount of work as in lifting the barbell? Explain.
(d) If the weightlifter drops the barbell, is work done on the bar-bell? Explain what happens in this situation. |
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| 55122 | (a) An RLC series circuit is in resonance. Which one of the following can you change without upsetting the resonance: (1) resistance, (2) capacitance, (3) inductance, or (4) frequency?
(b) A resistor, an inductor, and a capacitor have values of 500-Ω, 500 mH, and 3.5μF, respectively. They are connected in series to a power supply of 240 V with a frequency of 60 Hz. What values of resistance and inductance would be required for this circuit to be in resonance (without changing the capacitor)? |
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