Physics Current Electricity Level: Misc Level
Suppose a room has two 100-watt light bulbs. How much is the electricity bill per month (30 days) if the light bulbs are all you are paying for and they are used everyday 4 hours per day? The electricity cost is 15 cents per k Wh.
Physics Heat & Thermodynamics Level: Misc Level
Why must a room air conditioner be set partially out of a window? Why can,t it just be set in the center of a room and plugged in? Note that we are talking about an air conditioner, not a water evaporative cooler (swamp cooler).
Physics Heat & Thermodynamics Level: Misc Level
When an automobile engine overheats and the radiator water begins to boil, the car can still be driven some distance before catastrophic engine damage occurs. Why ? What determines the onset of really disastrous overheating?
Physics Properties Of Matter Level: Misc Level
Why don,t the sizes of different molecules present in a gas enter into the equation for the gas laws?
Physics Properties Of Matter Level: Misc Level
If your property must be measured with a metal tape in order to determine the amount of your property taxes, would you ratherr have it measured in the summer or the winter?Remember that your property will not significantly expand or contract with the change in season.
Physics Rotational Mechanics Level: Misc Level
On the basis of conservation of angular momentum, discuss why a helicopter must have more that one rotor(or propeller). Discuss two or more ways in which the second rotor (or propeller) can operate in order to keep the body of the helicopter stable.
Physics Rotational Mechanics Level: Misc Level
Stars originate as large bodies of slowly rotaing gas.Because of gravity, these clumps of gas slowly decrease in size.What happens to the angular velocity of a star as it shrinks?Explain.
Physics Rotational Mechanics Level: Misc Level
Derive an expression for the horizontal linear momentum impulse delivered to the rod by the pivot during the collision.
Physics Rotational Mechanics Level: Misc Level
Derive an expression for the maximum angle of deflection of the rod after the collision
Physics Rotational Mechanics Level: Misc Level
Derive an expression for the angular velocity of the rod+bullet (about the pivot) immediately after the collision.
Physics Rotational Mechanics Level: Misc Level
A Yo-Yo sits initially at rest on a table top. The coefficient of static friction between the Yo-Yo and surface of the table is 6/10. The Yo-Yo consists of two disks with a rather thick central spindle, around which is wrapped some string of negligible mass.the moment of inertia of the Yo-Yo is 2/5 m R^2; where R is the outer radius of the Yo- Yo and M is its mass.The radius of the spindle is R/4. Neglect the thickness of the thin'' massless'', string.
A Persion pulls straight up on the string with an applied force F.
What is the largest HORIZONTAL acceleration thatcan be given to the Yo-Yo by this method.Express your answer as a multiple of g.
Physics Magnetism,Magnetic Effects Of Current Level: Misc Level
2 identical wires have a weight per unit length of 1.o x10^-4 N/m. The wire are strung parallel to each other, one directly above the other with a distance of separation of 0.10 m.What current must be present in the 2 wires in order for the upper wire to ''float'' above the lower wire. Assume that the wires carry the same current in opposite directions.
Physics Magnetism,Magnetic Effects Of Current Level: Misc Level
A long straight wire carries a current of 5.00A .At one instant, a proton, 4.00 mm from the wire, travels at 1.50 x 10^3 m/s parallel to the wire, and in the same direction as the current. Find the magnitude and direction of the magnetic force on the proton.
Physics Magnetism,Magnetic Effects Of Current Level: Misc Level
A proton moves in a circular orbit of radius 14 cm in a uniform magnetic field of 0.35 T, directed perpendicular to the velocity of the proton. Find the orbital (linear)speed of the proton.
Physics Magnetism,Magnetic Effects Of Current Level: Misc Level
A proton moves with a speed of 1.0x10^5 m/s thorugh the Earth,s magnetic field which has a value of 55uT at a particular location. When the proton moves east, the magnetic force acting on it is maximum. When it moves northward, it experiences no magnetic force. Find the magnitude and dirrction of the maximum magnetic force.
