An echocardiogram uses 4.4 mhz ultrasound to measure blood flow in the aorta. the blood is moving away from the probe at 1.5 m/s . the speed of sound medium speed (m/s) air (0∘c) 331 air (20∘c) 343 helium (0∘c) 970 ethyl alcohol 1170 water 1480 human tissue (ultrasound) 1540 lead 1200 aluminium 5100 granite 6000 diamond 12,000 you may want to review ( pages 489 - 492) . part a what is the frequency shift of the reflected ultrasound

Which car has the most kinetic energy? a. a car of mass 1000 kg with a speed of 3 m/s b. a car of mass 2000 kg with speed 7 m/s c. a car of mass 1000 kg with speed 7 m/s d. a car of mass 2000 kg with speed 3 m/s

Part 1: a magnetic levitation or maglev train rides rails without touching them. explain how this works using your data. include the appropriate magnet drawing in your answer. part 2: two objects are near a bar magnet. one is about 1 cm away, while the other is 6 cm away. compare and contrast the magnetic force that affects each object. use your data to answer the question

Aperson gives a shopping cart an initial push along a horizontal floor to get it moving, and then lets go. the cart travels forward along the floor, gradually slowing as it moves. consider the horizontal force(s) on the cart while it is moving forward and slowing. which of the following statements is correct? (a) both a forward and a backward force are acting on the cart, but the forward force is larger. (b) only a forward force is acting which diminishes with time. (c) both a forward and a backward force are acting on the cart, but the backward force is larger. (d) only a backward force is acting, no forward force.