A box is pulled from rest at an angle of 20degrees across a level floor where there is friction. Once the box is moving it is Pulled for five seconds and then released and comes to a stop. What is the applied force if acceleration equals zero.

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.

Sort the images based on whether there's a force of attraction or repulsion between the magnets shown. attraction repulsion

Which best describes the difference between internal and thermal energy?