Author: Vita
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Tactics Box 9.1 Drawing a Before-and-After Visual Overview
Learning Goal: To practice Tactics Box 9.1 Drawing a before-and-after visual overview. During a collision, two objects exert forces on each other that vary in a complex way during the time of the collision. Using Newton’s second law to predict the outcome of a collision would thus be a daunting challenge. Nevertheless, some collisions have very…
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Momentum in an Explosion
A giant “egg” explodes as part of a fireworks display. The egg is at rest before the explosion, and after the explosion, it breaks into two pieces, with the masses indicated in the diagram, traveling in opposite directions. A) What is the momentum PA,i of piece A before the explosion? => PA,i = 0 kg*m/s B) During the…
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Impulse and Momentum Ranking Task
Six automobiles are initially traveling at the indicated velocities. The automobiles have different masses and velocities. The drivers step on the brakes and all automobiles are brought to rest. A) Rank these automobiles based on their momentum before the brakes are applied, from largest to smallest. => B) Rank these automobiles based on the magnitude…
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Colliding Balls
Balls A and B roll across a table, then collide and bounce off each other. The paths of the two balls are pictured (viewed from above) in the diagram. A) Which set of arrows best represents the change in momentum for balls A and B? => C B) Which of the following arrows indicates…
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Conservation of Energy Ranking Task
Six pendulums of various masses m are released from various heights h above a tabletop, as shown in the figures below. All the pendulums have the same length and are mounted such that at the vertical position their lowest points are the height of the tabletop and just do not strike the tabletop when released. Assume that…
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All Work and No Play
Learning Goal: To be able to calculate work done by a constant force directed at different angles relative to displacement If an object undergoes displacement while being acted upon by a force (or several forces), it is said that work is being done on the object. If the object is moving in a straight line and the displacement…
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Time Elapse
The back wall of an auditorium is 28.0 m from the stage. If you are seated in the middle row, how much time elapses between a sound from the stage reaching your ear directly and the same sound reaching your ear after reflecting from the back wall? The speed of sound in the air is 343 m/s.…
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What is its frequency?
A sinusoidal wave travels with speed 250 m/s. Its wavelength is 4.0 m. What is its frequency? v = 190 m/s λ = 30 m f= v/λ f= 190/3 =63.33
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Wavelength and Speed
The displacement of a wave traveling in the positive x-direction isy(x, t) = (3.5 cm) cos(2.7x – 92t), where x is in m and t is in s. v = 190 m/s λ= 3.0 m f = ? v=fλ f = v/λ f= 190/3 = 63.33 Displacement is y(n, t) = (3.5 cm) cos(2.7x – 92t) x =…
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Amplitude, Wavelength, and Frequency
The figure is a history graph at x = 0 m of a wave moving to the right at 2 m/s. What is the amplitude of this wave? A = How high it goes = 6cm What is the frequency of this wave? T = .6 F= 1/.6 = 1.66 = 1.7 Hz =2 Hz What…