What type of device is a refrigerator? A. A heat pump that uses work to move heat
B. A heat pump that uses heat to do work
C. A heat engine that uses work to move heat
D. A heat engine that uses heat to do work

Which describes an image that can be produced by a concave lens? the image is real and smaller than the object. the image is virtual and larger than the object. the image is virtual and smaller than the object. the image is real and larger than the object.

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.

What is the freezing point of radiator fluid that is 50% antifreeze by mass? kf for water is 1.86 ∘c/m.