Ametallic sphere is positively charged. the field at the center of the sphere due to this positive charge
a) dependent on the magnitude of the charge
b) zero
c) positive
d) negative

* explain as i'm lost on this one, : )

What do you think car designers do if the damage caused by a crash test is too severe?

Apebble is thrown into a calm lake, ripples are formed from the center and move outward. the water particles in the lake travel in a circular pattern that moves up and down on the surface of a lake, and the energy travels a) diagonally. b) downward. c) horizontally. d) upward.

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.