What are two ways in which ultrasound technology produces images? A. By using sound in frequencies that reflect off body tissues B. By the absorption of sound waves in the body C. By detecting the frequencies of emitted sound waves D. By measuring the time it takes for reflected sound waves to be detected​

Why does the equilibrium position of the spring change when a mass is added to the spring? will the mass oscillate around the new equilibrium position of the spring or the previous position without a mass attached to the spring? if the equilibrium position of the spring changes by 20 cm (assuming no initial mass) when a mass is added to the spring with constant 4.9 kg/s^2, what is the mass of the object attached to the spring?