calculate temperature

A tourist drops a 1-liter water-filled balloon from the top of a monument (170m high). If air resistance is negligible and almost all the motion energy heats the water, find the increase in temperature of the water when it hits the pavement. (hint: equate mgh in joules to the quantity of heat mc(change)T and express c, the specific heat capicity for water, in terms of joules rather than calories. Use conversion factor 4187J/kg degrees C

Which gas molecule moves faster?

In a mixture of hydrogen and oxygen gases at the same temperature, which molecules move faster and why? This is a question from a CONCEPTUAL physics class (no mathematical explanation please) in the chapter Heat Transfer

entropy principle

water evaporates from a salt solution and leaves behind salt crystals that have a higher degree of molecular oreder than the more randomly moving molecules in the salt water. Has the entropy principle been violated? why or why not? this is for a CONCEPTUAL physics class.

6 kg block

A 6.0 kg block is pushed 8.0 m up a rough 37 degree inclined plane by a horizontal force of 75N. If the initial speed of the block is 2.2m/s up the plane and a constant kinetic friction force of 25N opposes the motion, calculate the initial kinetic energy of the block, the work done by the 75N force, the work done by the friction force, the work done by gravity, the work done by the normal force, and the final kinetic energy of the block.

pendulum loops around a nail

A pendulum of mass M is attached to a string of length L. The other end of the string is attached to pivot point P. The string and mass are held horizontal and released so that the mass swings down. When the mass is at its lowest point, the string hits a nail a distance h above the mass, so that the mass loops around the nail. What the distance can h be above the mass, so that the string remains taut even when the mass loops to a point right above the nail? (NOTE: the string is taut as long as there is tension in the string)