When a ball is launched from the ground at a 45° angle to the horizontal, it falls back to the ground 50 m from the launch point. if it is launched at the same speed directly upward, (a) how high does it get? (b) how much longer does it spend in the air?

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.

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

The mass of the sun is 1.99×1030kg and its distance to the earth is 1.50×1011m. what is the gravitational force of the sun on the earth?