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If an electron (mass m = 9.11 * 10^-31 kg) in copper near the lowest possible temperature has a kinetic energy of 6.7 * 10^-19 J, what is the speed of the electron?
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Subject: Physics | Topic: Mechanics | ID: 153430
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$ 0 |
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If a baseball pitcher throws a fastball at a horizontal speed of 160 km/h, how long does the ball take to reach home plate 18.4 m away? ...MORE
Subject: Physics | Topic: Mechanics | ID: 153452
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$ 1 |
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A world speed record for bicycles was set in 1992 by Chris Huber riding Cheetah, a high-tech bicycle built by three mechanical engineering graduates. The record (average) speed was 110.6 km/h through a measured length of 200.0 m on a desert road. At the end of the run, Huber commented, "Cogito ergo zoom!" (I think, therefore I go fast!) What was Huber's elapsed time through the 200.0 m? ...MORE
Subject: Physics | Topic: Mechanics | ID: 153453
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$ 1 |
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An automobile travels on a straight road for 40 km at 30 km/h. It then continues in the same direction for another 40 km at 60 km/h. (a) What is the average velocity of the car during this 80 km trip? (Assume that it moves in the positive x direction.) (b) What is the average speed? (c) Graph x versus t and indicate how the average velocity is found on the graph. ...MORE
Subject: Physics | Topic: Mechanics | ID: 153454
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$ 1.5 |
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A top-gun pilot, practicing radar avoidance maneuvers, is man¬ually flying horizontally at 1300 km/h, just 35 m above the level ground. Suddenly, the plane encounters terrain that slopes gently upward at 4.3°, an amount difficult to detect visually (Fig.). How much times does the pilot have to make a correction to avoid flying into the ground? ...MORE
Subject: Physics | Topic: Mechanics | ID: 153455
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$ 1.5 |
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You drive on Interstate 10 from San Antonio to Houston, half the time at 55 km/h and the other half at 90 km/h. On the way back you travel half the distance at 55 km/h and the other half at 90 km/h. What is your average speed (a) ...MORE
Subject: Physics | Topic: Mechanics | ID: 153457
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$ 2 |
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Compute your average velocity in the following two cases:
(a) You walk 73.2 m at a speed of 1.22 m/s and then run 73.2 m at a speed of 3.05 m/s along a straight track, (b) You walk for along a straight track, (c) Graph x versus t for both cases and indicate how the average velocity is found on the graph.
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Subject: Physics | Topic: Mechanics | ID: 153458
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$ 1.5 |
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The position of an object moving along an x axis is given by x = 3t - 4t^2 + t^3, where x is in meters and t in seconds, (a) What is ...MORE
Subject: Physics | Topic: Mechanics | ID: 153460
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$ 1.5 |
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Two trains, each having a speed of 30 km/h, are headed at each other on the same straight track. A bird that can fly 60 km/h flies off the front of one train when they are 60 km apart and heads directly for the other train. On reaching the other train it flies directly back to the first train, and so forth. ...MORE
Subject: Physics | Topic: Mechanics | ID: 153461
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$ 1.0 |
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On two different tracks, the winners of the one-kilometer race ran their races in 2 min, 27.95 s and 2 min, 28.15 s. In order to conclude that the runner with the shorter time was indeed faster, how much longer can the other track be in actual length?
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Subject: Physics | Topic: Mechanics | ID: 153462
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$ 1.5 |
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The graph in Fig. is for an armadillo that scampers left (negative direction of x) and right along an x axis. (a) When, if ever, is the animal to the left of the origin on the axis? When, if ever, is its velocity (b) negative, (c) positive, or (d) zero? ...MORE
Subject: Physics | Topic: Mechanics | ID: 153463
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$ 1.5 |
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(a) If a particle's position is given by x = 4 - 12t + 3t^2 (where t is in seconds and x is in meters), what is its velocity at t = 1s?
(b) Is it moving in the positive or negative direction of x just then?
(c) What is its speed just then? (d) Is the speed
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Subject: Physics | Topic: Mechanics | ID: 153465
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$ 2 |
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The position of a particle moving along the x axis is given in centimeters by x = 9.75 + 1.50r^3, where t is in seconds. Calculate (a) the average velocity during the time interval t = 2.00 s to t = 3.00 s; (b) the instantaneous velocity at t = 2.00 s; (c) the instan¬taneous velocity at t == 3.00 s; (d) the instantaneous velocity at t = ...MORE
Subject: Physics | Topic: Mechanics | ID: 153466
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$ 2 |
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How far does the runner whose velocity-time graph is shown in Fig. travel in 16 s? ...MORE
Subject: Physics | Topic: Mechanics | ID: 153467
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$ 1.5 |
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Sketch a graph that is a possible description of position as a function of time for a particle that moves along the x axis and, at t = 1 s, has (a) zero velocity and positive acceleration; (b) zero velocity and negative acceleration; (c) negative velocity and positive ...MORE
Subject: Physics | Topic: Mechanics | ID: 153469
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$ 2 |
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What do the quantities (a) (dx/dt)^2 and (b) d^2/dt^2 represent? (c) What are their SI units? ...MORE
Subject: Physics | Topic: Mechanics | ID: 153470
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$ 1.0 |
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A frightened ostrich moves in a straight line with velocity described by the velocity-time graph of Fig. Sketch acceleration versus time. ...MORE
Subject: Physics | Topic: Mechanics | ID: 153471
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$ 1.0 |
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A particle had a speed of 18 m/s at a certain time, and 2.4 s later its speed was 30 m/s in the opposite direction. What were the magnitude and direction of the average acceleration of the particle during this 2.4 s interval? ...MORE
Subject: Physics | Topic: Mechanics | ID: 153473
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$ 1.0 |
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From t = 0 to t = 5.00 min, a man stands still, and from t = 5.00 min to t = 10.0 min, he walks briskly in a straight line at a constant speed of 2.20 m/s. What are (a) his average velocity vavg and (b) his average acceleration aavg in the time interval 2.00 min to 8.00 min? What are (c) vavg and (d) aavg in the time interval 3.00 min to 9.00 min? (e) Sketch x versus t and v versus t, and indicate how the answers to (a) through (d) can be obtained from the graphs. ...MORE
Subject: Physics | Topic: Mechanics | ID: 153474
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$ 2 |
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A proton moves along the x axis according to the equation x = 50t + 10t^2, where x is in meters and t is in seconds. Calculate (a) the average velocity of the proton during the first 3.0 s of its motion, (b) the instantaneous velocity of the proton at t = 3.0 s, and (c) the instantaneous acceleration of the proton at t = 3.0 s. (d) Graph x versus t ...MORE
Subject: Physics | Topic: Mechanics | ID: 153475
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$ 2 |
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