A boy rides his bicycle 3.00 km. The wheels have radius 30.0 cm. The total angle the tires rotate through during his trip is

Wo audio speakers are placed on a vertical rail. speaker a is placed at head-level while speaker b is place at some variable height, \delta yδy, above speaker a. both speakers receive simultaneous input from a sine-wave generator so the speakers each produce a pure sinusoidal sound wave with a wavelength of 0.531 meters. calculate the lowest height that speaker b can be placed above speaker a to produce a minimum of sound heard by person standing \delta x = 7.86δx=7.86 meters directly in front of speaker a.

Which statement best describes how private industry decides where to spend the money on research and development

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.