A 2000 kg car is driving down the road at a speed of 30 m/s. It suddenly slams on its brakes and stops in 40 m. Assuming a constant acceleration, find: a) the force applied by the brakes on the car.
b) the time required to stop the car.

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 feature indicates that mars resides in the inner region of the solar system

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.