If the distance between two objects is decreased to one fourth of the original distance, how will this decrease change the force of attraction between the objects? . a) the new force will be one eight of the original. b) the new force will be one sixteenth of the original. c) the new force will be eight times greater than the original. d) the new force will be sixteen times greater than the original

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.

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.

Debris produced by mining is called