Determine the x-, y-, and z-coordinates of the mass center of the fixture formed from thin metal plate of uniform thickness. Answers: x = y = Z 31° 9.0" i in. in. N z = in. 10.5" 2.5" 5.0" 2.5"

Figure P10.74 provides artists with human proportions. Notice that the center of mass moves lower in the body as the person grows. Explain this change. What does it tell you about human proportions as a person grows? FIGURE P10.74

Two identical balls are attached to a strong,lightweight rod (Fig. P14.3). The rod is supported by a horizontal pin at the systems center of mass. The balls are at rest. Is thesystem in static equilibrium? If not, why not? If so, which type of equilibrium is itstable, unstable, or neutral? Hint: What would happen if you displaced the balls slightly? FIGURE P14.3

A brass wire and a steel wire, both of the same length, are extended by 1.0 mm under the same force. Is the cross-sectional radius of the brass wire more, less, or equal to the cross-sectional radius of the steel wire? Explain. Youngs moduli for brass and steel are 1.0 1010 N/m2 and 2.0 1011 N/m2, respectively.

Review. A mixing beater consists of three thin rods, each 10.0 cm long. The rods diverge from a central hub, separated from each other by 120, and all turn in the same plane. A ball is attached to the end of each rod. Each ball has cross-sectional area 4.00 cm2 and is so shaped that it has a drag coefficient of 0.600. Calculate the power input required to spin the beater at 1 000 rev/min (a) in air and (b) in water.

You are part of a team in an engineering class that is working on a scale model of a new design for a life vest. You have been asked to find the mass of a piece of foam that will be used for flotation. Because the piece is too bulky to fit on your balance, you break it into two parts. You measure the mass of the first part as 128.3 0.3 g and the second part as 77.0 0.3 g. a. What are the maximum and minimum values for the total mass you might reasonably report? b. What is the best estimate for the total mass of the foam? Hint: Propagation of uncertainty is described in Appendix A.

Check Your Understanding If the normal force acting on each face of a cubical 1.0m3 piece of steel is changed by 1.0107 N. find the resulting change in the volume of the piece of steel.

In order to get his car out of the mud, a man ties one end of a rope to the front bumper and the other end to a tee 15 m away as shown below. He then pulls on the center of the rope with a force of 400 N, which causes its center to be displaced 0.30 m, as shown. What is the force of the rope on the car?

Consider the situation in Problem 25. Tests have shown that when people try to eyeball the proper angle for the ladder, theyare often off by as much as 9. Suppose the painter sets up theladder at too small an angle. a. At what maximum angle would rubber ladder tips on dryconcrete be unsafe? b. How likely is it for a person to make such a dangerousmistake?

A girl has a large, docile dog she wishes to weigh on a small bathroom scale. She reasons that she can determine her dogs weight with the following method. First she puts the dogs two front feet on the scale and records the scale reading. Then she places only the dog's two back feet on the scale and records the reading. She thinks that the sum of the readings will he the dogs weight. Is she correct? Explain your answer.