What is reverberation and give it's effects.?

The density of a substance is 4.0 g/cm3. if a sample of the substance has a volume of 25 cm3 then what is the mass

Asuppose a suitcase has a mass of (m) 30 kg and a net force (n) of 10 kg*m/s. what is the acceleration rate of the suitcasein m/s? show your work to support your answer.

Simple machines can a. increase force only b. decrease force only c. increase or decrease force