Let p be a point at a distance d from the center of a circle of radius r. the curve traced out by p as the circle rolls along a straight line is called a trochoid. (think of the motion of a point on a spoke of a bicycle wheel.) the cycloid is the special case of a trochoid with d = r. using the same parameter θ as for the cycloid and, assuming the line is the x-axis and θ = 0 when p is at one of its lowest points, parametric equations of the trochoid are x = rθ − d sin θ y = r − d cos θ. find the area under one arch of the trochoid found above for the case d < r.

An electric current in a wire will push or pull on a permanent magnet. which statement best explains how an electric current creates an electromagnetic force on another magnet?

Pl asaaap ! match the term to the correct description. a type of wave that transfers energy where the particles in the medium move perpendicular to the direction in which the energy is traveling. a type of wave that transfers energy where the particles in the medium move parallel to the direction in which the energy is traveling. movement that is back and forth, like an equal sign = a type of wave that transfers energy where the particles in the medium move in a circle motion while the energy travels left or right. movement that is like a t transfers energy from one location to another 1. wave 2. parallel movement 3. perpendicular movement 4. transverse wave 5. longitudinal wave 6. surface wave

6–43 a food department is kept at 2128c by a refrigerator in an environment at 308c. the total heat gain to the food department is estimated to be 3300 kj/h and the heat rejection in the condenser is 4800 kj/h. determine the power input to the compressor, in kw and the cop of the refrigerator.