10. Color Doppler ultrasound devices are often used to assess the health of the fetal heart during pregnancy. During a fetal ultrasound exam, a transducer placed against the expectant mother abdomen transmits ultrasound waves with a frequency of 3.500 MHz and receives the Doppler shifted echo from the fetal heart. If the echo received from the fetal heart by the transducer has a frequency of 3.498 MHz and 3.503 MHz from the left and right ventricles, respectively, what is the speed (in cm/s) of the blood flow in these two chambers of the fetal heart? The blood in the left ventricle flows away from the transducer while the blood in the right ventricle flows toward the transducer. Use v = 1,500 m/s for the speed of sound in tissue. left ventricle cm/s right ventricle cm/s 1. Estimate the total mass of the Earth's atmosphere? (The radius of the Earth is 6.37 x106 m, and atmospheric pressure at the surface is 1.01 x105 N/m2. (Hint: Calculate the surface area considering the Earth as a sphere). 2. The spring of the pressure gauge shown in the figure below has a force constant of 1 050 Mm, and the piston has a diameter of 1.40 cm. As the gauge is lowered into water in a lake, what change in depth causes the piston to move in by 0.440 cm? 3. The small piston of a hydraulic lift (see figure below) has a cross-sectional area of 2.70 cm2, and its large piston has a cross-sectional area of 203 cm2. What downward force of magnitude F1 must be applied to the small piston for the lift to raise a load whose weight is Fg = 14.2 kN? F: 4. A cube of wood having an edge dimension of 18.7 cm and a density of 653 kg/m3 floats on water. What is the distance from the horizontal top surface of the cube to the water level? 5. Ethanol with a density of 789 kg/m3 moves through a constricted pipe in steady, ideal flow. At the lower point shown in the figure below, the pressure is P1 = 1.95 x 104 Pa, and the pipe diameter is 8.00 cm. At another point y = 0.30 m higher, the pressure is P2 = 1.00 x 104 Pa and the pipe diameter is 4.00 cm. A tube is open at both its left and right ends. The tube starts at the le end, extends horizontally to the right, curves up and to the right, and extends horizontally to the right again. The right end is higher than its left end, and the change in height is labeled y. The pressure at the left end is labeled P1, and the pressure at the right end is labeled P2. (a) Find the speed of flow (in m/s) in the lower section. (b) Find the speed of flow (in m/s) in the upper section. (c) Find the volume flow rate (in m3/s) through the pipe. 6. In an engine, a piston oscillates with simple harmonic motion so that its position varies according to the expression, X = 4.00 cos (4t + 11/4) where x is in centimeters and t is in seconds. (a) At t = 0, find the position of the piston. (b) At t = 0, find velocity of the piston. (c) At t = 0, find acceleration of the piston. (d) Find the period and amplitude of the motion. 7. A metal sphere with a mass 7.50 kg is connected to a spring with a force constant of 375 N/m, and it oscillates horizontally with an amplitude of 4.45 cm. (a)What is the total mechanical energy (in J) of the spherespring system? (b)What is the maximum speed (in m/s) of the oscillating sphere? (c)What is the maximum magnitude of acceleration (in m/sz) of the oscillating sphere? 8. A wave is described by y = 0.0192 sin(kx - out), where k = 2.16 rad/m, a) = 3.52 rad/s, X and y are in meters, and t is in seconds. (a) Determine the amplitude of the wave. (b) Determine the wavelength of the wave. (c) Determine the frequency of the wave. (d) Determine the speed of the wave. 9. The sound intensity a distance d1 = 17.0 m from a lawn mower is 0.270 W/mz. What is the sound intensity a distance dz = 33.0 m from the lawn mower? (Enter your answer in W/m2.)