To describe and analyze motion in 2D (or higher), the use of vectors is the common method used. From your work with vectors, past and present, do you find the vector method a good (even best) way to analyze quantities in 2D? Are there other methods that could be used that will give the same results? From your own experience, what are the pros and cons in using the vector method?
Please no handwritten or typed responses - only typed answers.
In: Physics
Describe house wiring and specify how parallel or series connections of bulbs and resistors affect the functions.
In: Physics
A 72.0 kg swimmer jumps into the old swimming hole from a tree limb that is 3.95 m above the water.
Use energy conservation to find his speed just as he hits the water if he just holds his nose and drops in.
Express your answer to three significant figures.
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Part B
Use energy conservation to find his speed just as he hits the water if he bravely jumps straight up (but just beyond the board!) at 2.60 m/s .
Express your answer to three significant figures.
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nothing |
m/s |
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Part C
Use energy conservation to find his speed just as he hits the water if he manages to jump downward at 2.60 m/s .
Express your answer to three significant figures.
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| v = |
nothing |
m/s |
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In: Physics
A kestrel dives from a stationary hover, 20 m above the ground, to catch its prey, typically mice, on the ground. (a) If the kestrel’s acceleration toward the ground is due solely to free fall, calculate how long it takes to reach the ground. (3 points) (b) A field mouse can run at a top speed of 10 km/h, which it achieves starting from rest in 1 s. Assuming that the only way for the mouse to survive the kestrels attack is to find shelter, calculate the maximum distance the mouse can be from shelter to survive if it sees the kestrel as it begins its dive. (3 points) The mouse, in fact, only first sees the kestrel when it is at the mid point of the dive 10m above the ground. (c) Based only on your intuition (and not on any calculation), estimate how far the mouse needs to be from shelter to survive now. (1 point) (d) Calculate how far the mouse needs to be from shelter to survive in the new situation.
In: Physics
what is the frequency of a sound wave made by
In: Physics
If Emily throws the ball at an angle of 30∘ below the horizontal with a speed of 14m/s, how far from the base of the dorm should Allison stand to catch the ball? Assume the vertical distance between where Emily releases the ball and Allison catches it is 8.0m.
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During a tennis match, a player serves the ball at 25.6 m/s, with the center of the ball leaving the racquet horizontally 2.34 m above the court surface. The net is 12.0 m away and 0.900 m high. When the ball reaches the net, (a) what is the distance between the center of the ball and the top of the net? (b) Suppose that, instead, the ball is served as before but now it leaves the racquet at 5.00° below the horizontal. When the ball reaches the net, what now is the distance between the center of the ball and the top of the net? Enter a positive number if the ball clears the net. If the ball does not clear the net, your answer should be a negative number. Use g=9.81 m/s2.
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The nucleus of 8Be, which consists of 4 protons and 4 neutrons, is very unstable and spontaneously breaks into two alpha particles (helium nuclei, each consisting of 2 protons and 2 neutrons). (a) What is the force between the two alpha particles when they are 3.40 10-15 m apart? Your response differs from the correct answer by more than 10%. Double check your calculations. N (b) What is the initial magnitude of the acceleration of the alpha particles due to this force? Note that the mass of an alpha particle is 4.0026 u. m/s2
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A passenger on a moving train walks at a speed of 1.60 m/s due north relative to the train. The passenger's speed with respect to the ground is 4.5 m/s at an angle of 35.0° west of north. What are the magnitude and direction of the velocity of the train relative to the ground? _______m/s direction ______ ° west of north
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the force exerted by a spring is given by the equation
where F is the force (in Newtons), xis the displacement of the spring from the equilibrium position (in centimeters), and k is a spring constant
Create an Excel worksheet showing force as a function of displacement for two springs whose spring constants are 0.1 N/cm and 0.5 N/cm. Use displacements ranging from 0 to 20 cm (i.e. let x = 0, 1, 2 … 20 cm).
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From the window of a building, a ball is tossed from a height y0 above the ground with an initial velocity of 7.90 m/s and angle of 19.0° below the horizontal. It strikes the ground 6.00 s later.
(a) If the base of the building is taken to be the origin of the coordinates, with upward the positive y-direction, what are the initial coordinates of the ball? (Use the following as necessary: y0. Assume SI units. Do not substitute numerical values; use variables only.)
xi =
yi =
(b) With the positive x-direction chosen to be out the window, find the x- and y-components of the initial velocity.
vi, x = _______ m/s
vi, y = _______m/s
(c) Find the equations for the x- and y-components of the position as functions of time. (Use the following as necessary: y0 and t. Assume SI units.)
x =_____ m
y = ____m
(d) How far horizontally from the base of the building does the ball strike the ground?
_______m
(e) Find the height from which the ball was thrown.
______m
(f) How long does it take the ball to reach a point 10.0 m below the level of launching?
Please show work
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Express the following quantities using the prefixes given in the
table. (Enter a numeric value between 0.1 and 100, and choose the
appropriate units.)
| Power | Prefix | Abbreviation |
|---|---|---|
| 10−24 | yocto | y |
| 10−21 | zepto | z |
| 10−18 | atto | a |
| 10−15 | femto | f |
| 10−12 | pico | p |
| 10−9 | nano | n |
| 10−6 | micro | µ |
| 10−3 | milli | m |
| 10−2 | centi | c |
| 10−1 | deci | d |
| 103 | kilo | k |
| 106 | mega | M |
| 109 | giga | G |
| 1012 | tera | T |
| 1015 | peta | P |
| 1018 | exa | E |
| 1021 | zetta | Z |
| 1024 | yotta | Y |
(a) 3 ✕ 1011 m
------ Select ------ yoctometers zeptometers attometers
femtometers picometers nanometers micrometers millimeters
centimeters decimeters dekameters kilometers megameters gigameters
terameters petameters exameters zettameters yottameters
(b) 6 ✕ 10-5 s
------ Select ------ yoctoseconds zeptoseconds
attoseconds femtoseconds picoseconds nanoseconds microseconds
milliseconds centiseconds deciseconds dekaseconds kiloseconds
megaseconds gigaseconds teraseconds petaseconds exaseconds
zettaseconds yottaseconds
(c) 4 ✕ 10-10 g
------ Select ------ yoctograms zeptograms attograms
femtograms picograms nanograms micrograms milligrams centigrams
decigrams dekagrams kilograms megagrams gigagrams teragrams
petagrams exagrams zettagrams yottagrams
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In this module, you will look for an article or news story/video that relates to one or more of the following topics:
Conservative versus non-conservative forces
Potential Energy
Conservation of energy (as it relates to physics, not environmental friendliness)
These are pretty broad topics, but a few ideas should spring readily to mind.
By the end of the third day of the module, create a thread with a 250-word post including one or more of the topics listed above, an active hyperlink to your resource, a summary of the resource itself, a summary of the material you are learning in this module as it relates to your resource, and an explanation of how the topic or resource ties to your everyday life.
Question is not related to a lecture. Just requires an article, explanation of the article, and how Conservative versus non-conservative forces, Potential Energy, or Conservation of energy (as it relates to physics, not environmental friendliness) apply to that article.
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A 28.0-kg block is connected to an empty 2.56-kgbucket by a cord running over a frictionless pulley. The coefficient of static friction between the table and the block is 0.41 and the coefficient of kinetic friction between the table and the block is 0.32. Sand is gradually added to the bucket until the system just begins to move. Ignore mass of cord. (Figure 1)
Calculate the mass of sand added to the bucket.
Calculate the acceleration of the system.
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Calculate the number of free electrons per cubic centimeter (and per atom) for sodium from resistance data (relaxation time 3.1*10-14 s)
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