Multiple ChoiceAbout 50,000 years ago, a meteor crashed into the earth near present-day Flagstaff, Arizona. Some estimates suggest this meteor had a mass of about 1.4×108 kg and released 1×1016 J of energy when it slammed into the Earth. Calculate the approximate speed of this meteor before impact.2883views63rank1comments
Multiple ChoiceA particle with mass m and velocity v has kinetic energy K. What is the kinetic energy of a particle with mass m/2 and velocity 2v?513views
Multiple ChoiceBlock A has mass 20kg and block B has mass 50kg. Starting from rest, the two blocks are pushed by identical forces through a distance of 10m. Which block (if either) is going faster at end of the 10m? Which block (if either) has the greatest kinetic energy at the end of the 10m?384views
Multiple ChoiceWhat is the kinetic energy of a 500kg car traveling at 27m/s (about 60mph)?293views
Textbook Question(II) For a satellite of mass in a circular orbit of radius r_S around the Earth, determine(a) its kinetic energy K171views
Textbook Question(c) Is it reasonable that a 30-kg child could run fast enough to have 100 J of kinetic energy?485views
Textbook Question(I) At room temperature, an oxygen molecule, with mass of 5.31 x 10⁻²⁶ kg, typically has a kinetic energy of about 6.21 x 10⁻²¹ J . How fast is it moving?160views
Textbook QuestionA mother has four times the mass of her young son. Both are running with the same kinetic energy. What is the ratio v(son)/v(mother) of their speeds?597views
Textbook QuestionAt what speed does a 1000 kg compact car have the same kinetic energy as a 20,000 kg truck going 25 km/h?465views
Textbook QuestionA 45 g bug is hovering in the air. A gust of wind exerts a force F (→ above F) = (4.0î-6.0ĵ) x 10¯² N on the bug. (b) What is the bug's speed at the end of this displacement? Assume that the speed is due entirely to the wind.465views
Textbook QuestionHow much work does tension do to pull the mass from the bottom of the hill (θ = 0) to the top at constant speed? To answer this question, write an expression for the work done when the mass moves through a very small distance ds while it has angle θ, replace ds with an equivalent expression involving R and dθ , then integrate.368views
Textbook QuestionA Porsche 944 Turbo has a rated engine power of 217 hp. 30% of the power is lost in the engine and the drive train, and 70% reaches the wheels. The total mass of the car and driver is 1480 kg, and two-thirds of the weight is over the drive wheels. (c) How long does it take the Porsche to reach the maximum power output?240views
Textbook QuestionA Porsche 944 Turbo has a rated engine power of 217 hp. 30% of the power is lost in the engine and the drive train, and 70% reaches the wheels. The total mass of the car and driver is 1480 kg, and two-thirds of the weight is over the drive wheels. (b) If the Porsche accelerates at aₘₐₓ, what is its speed when it reaches maximum power output?266views
Textbook QuestionA Porsche 944 Turbo has a rated engine power of 217 hp. 30% of the power is lost in the engine and the drive train, and 70% reaches the wheels. The total mass of the car and driver is 1480 kg, and two-thirds of the weight is over the drive wheels. (a) What is the maximum acceleration of the Porsche on a concrete surface where μₛ = 1.00 ? Hint: What force pushes the car forward?870views
Textbook QuestionA 150 g particle at x = 0 is moving at 2.00 m/s in the + x - direction. As it moves, it experiences a force given by Fₓ = (0.250 N) sin (x/2.00 m) . What is the particle's speed when it reaches x = 3.14 m ?798views
Textbook QuestionT ─ (1500 kg) (9.8 m/s²) = (1500 kg) (1.0 m/s²) P = T (2.0 m/s) (a) Write a realistic problem for which this is the correct equation(s).259views
Textbook QuestionA particle moving on the x-axis experiences a force given by Fx = qx², where q is a constant. How much work is done on the particle as it moves from x=0 to x=d?510views1rank
Textbook QuestionT ─ (1500 kg) (9.8 m/s²) = (1500 kg) (1.0 m/s²) P = T (2.0 m/s) (c) Finish the solution of the problem.202views
Textbook QuestionThe gravitational attraction between two objects with masses mᴀ and mᴃ, separated by distance 𝓍, is F = Gmᴀmᴃ/𝓍², where G is the gravitational constant. (b) If one mass is much greater than the other, the larger mass stays essentially at rest while the smaller mass moves toward it. Suppose a 1.5 x 10¹³ kg comet is passing the orbit of Mars, heading straight for the sun at a speed of 3.5 x 10⁴ m/s. What will its speed be when it crosses the orbit of Mercury? Astronomical data are given in the tables at the back of the book, and G = 6.67 x 10 ¯¹¹ Nm²/kg² ..332views
Textbook QuestionCALC An object moving in the xy-plane is subjected to the force F(arrow on top) =(2xy î+x² ĵ) N, where x and y are in m. c. Is this a conservative force?273views
Textbook QuestionCALC An object moving in the xy-plane is subjected to the force F(arrow on top) =(2xy î+x² ĵ) N, where x and y are in m. a. The particle moves from the origin to the point with coordinates (a, b) by moving first along the x -axis to (a, 0) , then parallel to the y -axis. How much work does the force do?573views
Textbook Question(II) Two Earth satellites, A and B, each of mass m = 950 kg , are launched into circular orbits around the Earth’s center. Satellite A orbits at an altitude of 4800 km, and satellite B orbits at an altitude of 12,600 km.(b) What are the kinetic energies of the two satellites?129views
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