A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.450 m/s. The total mass of the sled, man, and rock is 97.5 kg. The mass of the rock is 0.280 kg and the man can throw it with a speed of 17.5 m/s. Both speeds are relative to the ground. Determine the speed of the sled (in m/s) if the man throws the rock forward (i.e., in the direction the sled is moving).
Determine the speed of the sled (in m/s) if the man throws the rock directly backward.
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Can you use the same variational wave function as in (2) to determine the energy of the first excited state of the one-dimensional harmonic oscillator? Why or why not?
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Problem: A popular brain teaser is to consider the motion of a quarter when you roll it around another one; how many times will Washington’s head rotate while the quarter rolls once around the other fixed quarter. This problem is a generalization of this puzzle. Assume a system of units such that the radius of the quarter is equal to one unit. Your task is to determine a parameterized position vector describing the location of the white dot on the rim of the rolling quarter. As the quarter moves, this dot will sweep out a curve in space. Derive the parametric equations for the curve and plot it. Include a copy or sketch of your plot. Hint: The center of the rolling quarter travels along a circle of radius 2
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You're driving down the highway late one night at 20 m/s when a deer steps onto the road 39 m in front of you. Your reaction time before stepping on the brakes is 0.50 s , and the maximum deceleration of your car is 12 m/s2 . How much distance is between you and the deer when you come to a stop? What is the maximum speed you could have and still not hit the deer?
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What are the recent technology of x-ray fluoroscopy?
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1.A radioactive sample has a half-life of 2.5 min. What fraction of the sample is left after 40 min?
2. The energy of a 2.00 keV electron is known to within
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Moving with proton i = (2i + 3j - k) m / s velocity in a region where uniform magnetic field B = (21i + 4j + k) T and uniform electric field E = (4i-j-2k) V / m It is. a) Calculate the electrical, magnetic and total force acting on the particle? b) How much angle does the total force vector with the positive x-axis? c) What is the acceleration of the proton? (mp = 1.6x10 ^ 27kg for proton q = 1.6x10 ^ -19C)
B=(2i+4j+k)
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a) A photon of frequency 8.2 x 1015 Hz is incident upon a photoelectric apparatus containing a metal whose threshold frequency is 3.6 x 1015 Hz. What is the stopping voltage?
b)A photon of frequency 7.2 x 1015 Hz is incident upon a metal whose threshold frequency is 8.9 x 1014 Hz. What is the speed of the photoelectron?
c)Electrons are ejected from a photoelectric surface with a maximum speed of 4.20 x 105 m/s. If the work function of the metal is 2.55 eV, what is the wavelength of the incident light?
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2 identical magnets are arranged with like poles facing each other on a frictionless 30 degree slope. The magnet on the lower position is held in place and can't move. the magnet in the higher position on the track is held in place by the balance of the upslope force due to the magnetic repolsion between the magnets and the downslope force due to the weight of the magnet. The mass of the magnets is 50 grams each. The distance between the magnets is 5 cm.
(1) what is the magnetic force between the magnets? answer in newtons.
(2) If the strength of the magnetic force between the magnets is of the form: F= C*(1/r^3), what is the separation between the magnets when the angle of the slope is only 20 degrees? answer in cm.
(3) what would the angle of the slope be to get a separation of 7.11 cm? answer in degrees.
(4) what would the separation be at a slope of 5 degrees? answer in cm.
(5) what would the force between the magnets be if the slope was 5 degrees? answer in Newtons.
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A guy named Joe, who is 1.6 meters tall, enters a room in which someone has placed a large convex mirror with radius of curvature RRR equal to 30 meters. The mirror has been cut in half, so that the axis of the mirror is at ground level. (Figure 1)As Joe enters the room, he is 5 meters in front of the mirror, but he is looking the other way, so he fails to see it. When he turns around, he is startled by his own image in the mirror. Figure1 of 2The figure shows a man standing on a horizontal x-axis in front of a vertical mirror. The mirror is convex. |
Part A How far away does the image appear to Joe? Express your answer in meters, to three significant figures or as a fraction. View Available Hint(s)
SubmitPrevious Answers Incorrect; Try Again; 7 attempts remaining This is the image distance (i.e., the distance from the mirror to the image). You want the distance from Joe to the image, so you must combine this distance with Joe's distance from the mirror. Should you add or subtract? Part B What is the image height yimyimy_im that Joe sees in the mirror? Express your answer in meters, to three significant figures or as a fraction. View Available Hint(s)
Submit Joe is so startled by his image that he falls forward. (Assume that his feet stay at the same position.)(Figure 2) Part C Now what is the length (i.e., the distance from head to toe) of Joe's image? Express your answer in meters, to three significant figures or as a fraction. View Available Hint(s)
Submit Provide FeedbackNext |
Incorrect. Incorrect; Try Again; 7 attempts remaining. Feedback. This is the image distance (i.e., the distance from the mirror to the image). You want the distance from Joe to the image, so you must combine this distance with Joe's distance from the mirror. Should you add or subtract? End of feedback.
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Two friends hold on to a rope, one at each end, on a smooth, frictionless ice surface. They skate in a circle about an axis through the center of the rope and perpendicular to the ice. The mass of one friend is 81.0 kg and the other has a mass of 125.0 kg. The rope of negligible mass is 4.5 m long and they move at a speed of 4.50 m/s.
(a) What is the magnitude of the angular momentum of the system comprised of the two friends? kg · m2/s
(b) They now pull on the rope and move closer to each other so that the rope between them is now half as long. Determine the speed with which they move now. m/s
(c) The two friends have to do work in order to move closer to each other. How much work did they do? J
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| The diameter of Mars is 6794 kmkm , and its minimum distance
from the earth is 5.58×107 kmkm .
For related problem-solving tips and strategies, you may want to view a Video Solution of Image from a concave mirror. |
Part A When Mars is at this distance, find the diameter of the image of Mars formed by a spherical, concave telescope mirror with a focal length of 1.80 mm . Express your answer in millimeters.
SubmitRequest Answer Part B Where is the image located? Where is the image located?
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