Master Physics with Fun Quizzes & Brain Teasers!

A book sliding across a horizontal tabletop slows until it comes to rest. Describe what change, if any, occurs in the book's kinetic energy and internal energy as it slows.
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A spaceship takes off vertically from rest with an acceleration of 28.5 m/s^2.a) What magnitude of force (in Newtons) is exerted on a 59.0 kg astronaut during takeoff?b) Express this force as a multiple of the astronaut's weight on Earth?
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a frictionless tracm contains a circular section of radius r as shown
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At t = 0 a rock is projected from ground level with a speed of 15.0 m/s and at an angle of 53.0 above the horizontal. Neglect air resistanceThree parts answer all partsA. At what two times t1t1 and t2t2 is the rock 5.00 mm above the ground? (Suppose that t1Express your answers in seconds separated by a comma.BWhat are the horizontal and vertical components of the velocity of the rock at time t1t1 calculated in part A? Let v0xv0x and v0yv0y be in the positive xx- and yy-directions, respectively.Express your answers in meters per second. Enter the x and y components of the vector separated by a comma.CWhat are the horizontal and vertical components of the velocity of the rock at time t2t2 calculated in part A? Let v0xv0x and v0yv0y be in the positive xx- and yy-directions, respectively.Express your answers in meters per second. Enter the x and y components of the vector separated by a comma.
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The 100 m dash can be run by the best sprinters in 10.0 s. A 60 kg sprinter accelerates uniformly for the first 47 m to reach top speed, which he maintains for the remaining 53 m.a. What is the average horizontal component of the force exerted on his feet by the ground during acceleration?b. What is the speed of the sprinter over the last 50 m of the race?
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a loaf of bread is removed from an oven at350 f and cooled in a room whose temperature is70 f. ifthe bread cools to210 f in 20 minutes,how much longer will it take the bread to cool to140 f.
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The 20-g bullet is travelling at 400 m/s when it becomes embedded in the 2-kg stationary block. The coefficient of kinetic friction between the block and the plane is ?k = 0.3. (Figure 1)Part ADetermine the distance the block will slide before it stops.Express your answer to three significant figures and include the appropriate units.
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A mass less spring is between a 1-kilogram mass and a 3-kilogram mass as shown, but is not attached to either mass. Both masses are on a horizontal friction less table. In an experiment, the 1-kilogram mass is held in place and the spring is compressed by pushing on the 3-kilogram mass. The 3-kilogram mass is then released and moves off with a speed of 10 meters per second. a. Determine the minimum work needed to compress the spring in this experiment. In a different experiment, the spring is compressed again exactly as above, but this time both masses are released simultaneously and each mass moves off separately at unknown speeds. b. Determine the final velocity of each mass relative to the cable after the masses are released.Read more on
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a. using x = weight and y = number of satellites, t a poisson loglinear model. report the prediction equation. b. estimate the mean of y for female crabs of average weight 2.44 kg.
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a battery of emf and negligible internal resitance, three identical incandescent lightbulbs and a switch s that is initially open are connected in the circuit shown above
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two stationary point charges of unknown magnitude and sign are isolated from all other charges. if the electric field strength is zero at the midpoint of the line joining them, which of the following can be concluded about the charges? two stationary point charges of unknown magnitude and sign are isolated from all other charges. if the electric field strength is zero at the midpoint of the line joining them, which of the following can be concluded about the charges? they are equal in magnitude but opposite in sign. they are not necessarily equal in magnitude but have opposite signs. none of the above can be concluded without additional information. they are equal in magnitude and have the same sign. they are not necessarily equal in magnitude but have the same sign.
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which is true concerning work and the spring constant, k a) the spring constant creates a positively linear relationship when plotted on a work vs. displacement graph. b) the spring constant creates a constant relationship when plotted on a force vs. displacement graph. c) there is no relationship between work and the spring constant, k. d) the spring constant creates a positively linear relationship when plotted on a force vs. displacement graph
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what is the correct rule? select one: a. if an athlete lifts the barbell 5cm off the platform and replaces it on the platform with 30 seconds remaining on the clock; he/she cannot try the lift again b. if an athlete lifts the barbell off the platform and replaces it on the platform, he/she can try the lift again unless the barbell has reached the height of the knees. c. if an athlete lifts the barbell approximately 10cm from the platform and replaces it on the platform with 15 seconds remaining on the clock he/she cannot try the lift again.
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during an echocardiogram, the device emits ultrasound waves at a frequency of 206000 hz. the waves are reflected off of red blood cells moving toward the device at a speed of 1.1 m/s. what is the absolute value of the difference between the frequency emitted by the device and the frequency detected by the device? (speed of sound in blood is 1500 m/s) (include units with answer)
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Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column. Use each word only once.1. A massive object can distort the light of more distant objects behind it through the phenomenon that we call____2. _____are defined as subatomic particles that have more mass than neutrinos but do not interact with light.3. The_____of spiral galaxies provide strong evidence for the existence of dark matter.4. Matter made from atoms, with nuclei consisting of protons and neutrons, represents what we call_____matter.5. Models show that the______of the universe is better-explained when we include the effects of dark matter along with the effects of luminous matter.6. Matter consisting of particles that differ from those found in atoms is generally referred to as_____matter.GRAVITATIONAL LENSING - ROTATION CURVES - WIMPS - ORDINARY (OR BARYONIC) - LARGE-SCALE STRUCTURE - EXOTIC (OR NONBARYONIC)
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What is the strength of a magnetic field 5.0 cm from a long straight wire carrying 4.0 A of current?a) 3.8 A -- 10-6 Tb) 4.9 A -- 10-6 Tc) 1.6 A -- 10-5 Td) 4.7 A -- 10-5 T
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Multiple star systems in our galaxyA) are extremely rare, making up less than 1% of the totalB) are very common, making up about 50% of the totalC) are fairly common, making up around 30% of the totalD) do not exist
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how does the use of prefixes make each expression and conversation of measurement easier
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which of the following best describes how the greenhouse effect works? which of the following best describes how the greenhouse effect works? greenhouse gases absorb infrared light coming from the sun, and this absorbed sunlight heats the lower atmosphere and the surface.
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consider a stick 1.00 m long and its moments of inertia about axes perpendicular to the stick's length and passing through two different points on the stick: first, a point at its center and second, a point 44 cm from one end. calculate the ratio , the ratio of the second moment of inertia to the first.
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How much energy can be stored in a spring with k = 470 N/m if the maximum possible stretch is 20 cm?
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which requires more work: lifting a 8 kg rock to a height of 6 m without acceleration, or accelerating the same rock horizontally from rest to a speed of 13 m/s?
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5.1.1 spring/mass systems: free undamped motion 1. a mass weighing 4 pounds is attached to a spring whose spring constant is 16 lb/ft. what is the period of simple harmonic motion?
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81. find the momentum and energy of a 1.0- photon.
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