1. A hollow cylindrical copper tube is 1.50m long and has an outside diameter of 3.50m and an inside diameter of 2.50com. How much does it weigh?

Answer: 61.6 N

2. If the force on the tympanic membrane (tympanum) increases by approximately 1.5 N above the force of atmospheric pressure, the membrane is damaged. When diving in the ocean, below what depth could your tympani begin to be damaged? The tympanum usually has a diameter of 8.2 mm.

Answer: 2.8 m

3. A 950 kg cylindrical buoy can float vertically in salt water. The diameter of the buoy is 0.900 m. Calculate the additional distance the buoy will sink when an 80.0 kg man is placed on top of the buoy.

Answer: 0.122 m

4. At one point in a horizontal pipe, the water velocity is 2.50 m/s and the gauge pressure is 1.80 * 10^4 Pa. Calculate the gauge pressure at a second point where the cross-sectional area is twice as large as at the first point.

Answer: 2.03

5. A uniform rod is 2.00 m long and has a mass of 1.80 kg. The rod is attached to a clamp weighing 2.40 kg. How far must the center of gravity of the clamp be from the left end of the rod so that the center of gravity of the composite object is 1.20 m from the left end of the rod?

Answer: 1.35

6. A 300 N uniform hatch is closed, hinged on one side, above the floor. Calculate the total upward force required to begin to open it, and the total force exerted on the hatch by the hinges: a) if the upward force is applied at the center of the hatch and b) if the upward force is applied at the center of the edge opposite the hinges.

7. A uniform ladder 5.0 m long weighing 160 N rests against a frictionless vertical wall with its base 3.0 m from the wall. The coefficient of static friction between the base of the ladder and the ground is 0.40. A 740 N man slowly climbs the ladder. Begin by drawing a free-body diagram of the ladder. (a) What is the maximum frictional force the ground can exert on the ladder at its base? (b) What is the frictional force when the man has climbed 1.0 m along the ladder? (c) How far can the man climb before the ladder slips?

Answer: A) 360 N. B) 171 N. C) 2.7 m

8. A relaxed biceps requires a force of 25.0 N to lengthen 3.0 cm; the same muscle under maximum tension requires a force of 500 N for the same lengthening. Calculate Young's modulus for the muscle tissue under both conditions, if we consider it as a uniform cylinder of 0.200 m in length and cross-section of 50.0 cm^2.

Answer: Relaxed: 3.33*10^4 Pa. Maximum tension: 6.67*10^5 Pa

9. A solid gold ingot is removed from the hold of the sunken RMS Titanic. a) What happens to its volume as it changes from the pressure in the ship to the lower pressure at the sea surface? b) The pressure difference is proportional to the depth. How many times larger would the volumetric change have been, if the ship had been at twice the depth? c) The volumetric modulus of lead is one-fourth of the modulus of gold. Calculate the rate of volumetric change of a solid ingot of lead and a solid ingot of gold of equal volume, for the same change in pressure.

10. A pickup truck has a 3.00 m wheelbase. Normally, 10,780 N rests on the front wheels and 8820 N rests on the rear wheels when the vehicle is parked on level pavement. a) A load of 3600 N is placed on the rear tug (an attachment that is placed on the bumper to hitch a trailer), 1.00 m behind the rear axle. How much weight now rests on the front wheels, and on the rear wheels? b) How much weight would have to be placed on the rear hitch for the front wheels to lift off the ground?

Answer: A) 1.6. B) 1.65w = 3.3*10^4 N

11. A 90.0 N uniform table is 3.6 m long, 1.0 m high, and 1.2 m wide. A weight of 1500 N is placed 0.50 m from one end of the table, at a distance of 0.60 m from each of the legs on that side. Draw a free-body diagram for the table and calculate the force that each of the four legs exerts on the table.

12. A mass of 12.0 kg attached to the end of an aluminum wire with an unstretched length of 0.50 m rotates in a vertical circle with a constant angular velocity of 120 rev/min. The cross-sectional area of the wire is 0.014 cm^2. Calculate the elongation of the wire when the mass is a) at the lowest point of the path and b) at the highest point of the path.

Answer: A) 0.54 cm. B) 0.42 cm