Physics Work,Power & Energy Level: Misc Level
# Calculate the change in internal energy for each of the following systems:
Physics Heat & Thermodynamics Level: Misc Level
2 grams of steam at 100 degrees Celsius turns to ice at 0 degrees Celsius.
Physics Heat & Thermodynamics Level: Misc Level
2 grams of steam at 100 degrees Celsius turns to ice at 0 degrees Celsius.
Physics Heat & Thermodynamics Level: Misc Level
2 grams of ice water at 0 degrees Celsius freezes to ice at 0 degrees Celsius.
Physics Heat & Thermodynamics Level: Misc Level
2 grams of boiling water at 100 degrees Celsius cools to ice water at 0 degrees Celsius.
Physics Heat & Thermodynamics Level: Misc Level
2 grams of steam at 100 degrees Celsius condenses to water at 100 degrees Celsius.
Physics Properties Of Matter Level: Misc Level
Suppose a 1 meter long bar expands 0.5 centimeters when heated. By how much will a 100 meter long bar of the same material expand when similarly heated?
Physics Heat & Thermodynamics Level: Misc Level
How many calories are needed to raise 500 grams of water from 25 degrees Celsius to 40 degrees Celsius?
Physics Rotational Mechanics Level: Misc Level
Two astronauts each having a mass of 75 kg are connected by a 10 m rope of negligible mass. They are isolated in space, moving in circles around the point halfway between them at a speed of 5 m/s. Treating the astronauts as particles. Calculate the magnitude of angular momentum, the rotational energy of the system.(By pulling on the rope the astronauts shorten the distance between them to 5 m) what is the new angular momentum of the system. what are their new speeds, what is the new rotational energy of the system,how much work is done by the astronauts in shorting the rope?
Physics Rotational Mechanics Level: Misc Level
A 60 kg woman stands at the rim of a horozontal turntable having a moment of inertia of 500 kg* m^2 and a radius of 2 m. The turntable is initially at rest and is free to rotate about a frictionless, vertical axle through its center.The woman then starts walking around the rim clockwise (as viewed from above the system) at a constans speed of 1.5 m/s relative to the earth. In what direction and with what angular speed does the turntable rotate? and How much work does the woman do to set herself and the turntable in motion?
Physics Rotational Mechanics Level: Misc Level
A solid horozontal cylinder of mass 10 kg and radius 1 m rotates with an angular speed of 7 rad/s about a fixed vertical axis through its center. A . 25 kg piece of putty is dropped vertically on the cylinder at a point. 9 m from the center of rotation and sticks to the cylinder. the Determine the final angular speed of the system.
Physics Rotational Mechanics Level: Misc Level
A 15 kg merry go round in the shape of a uniform solid horozontal disk of radius 1.5 m is set in motion by wrapping a rope about the rim of the disk and pulling on the rope. what constant force must be exerted on the rope to bring the merry go round from rest to an angular speed of . 5 rev/s in 2 sec.
Physics Rotational Mechanics Level: Misc Level
A model airplane with mass. 75 kg is tethered to a wire so that it flies in a circle 30 m in radius. The airplane engine provides a thrust of . 8 N perpendicular to the tethering wire. Find the torque the net thrust produces about the center of the circle. Find the angular acceleration of the airplane when it is in level flight. Find the linear acceleration of the airplane tangent to its flight path.
Physics Force & Laws Of Motion Level: Misc Level
(b) For a banked curve with friction, the frictional force on a fast- moving car is directed down the bank.If the coefficient of static friction between the tires and ground is ? s, what is the maximum speed a car can safely maintain on the curve? Give numerical answers for ? s =0.050. (This explains why highway curves are more dangerous when wet or icy)
Physics Circular Motion Level: Misc Level
If a car goes around a curve too fast, it tends to slide out of the curve since the frictional force is not large enough to provide the necessary centripetal force . one way to get around this is to create a banked curve in which a centripetal force is present even in the absence of friction, as shown below . the vertical component of the normal force N equals mg, and the horizontal component of the normal force provides the centripetal force .
(a) Calculate an expression for the maximum speed a car can maintain around a curve of radius R banked at angle ? E valuate it for R=200 m and ? =10%
