1. A 100-lb force is pulling a 200-lb block as shown. The coefficient of static friction between the block and the floor is μs = 0.6 and the coefficient of kinetic friction is uk = 0.4. a. What is the friction force between the block and the floor? 6. Will the block move? W: 2006 10016

An astronaut has a mass of 68 kg. What is the weight of the astronaut on Earth at sea level? What are the mass and the weight of the astronaut on the Moon, and on Mars? What is the ratio of the pressure exerted by the astronauts shoe on Earth to Mars?

Determine the specific gravity of the following materials: gold ( = 1208 lb/ft3), platinum ( = 1340 lb/ft3), silver ( = 654 lb/ft3), sand ( = 94.6 lb/ft3), freshly fallen snow ( = 31 lb/ft3), tar( = 75 lb/ft3), hard rubber ( = 74.4 lb/ft3).

In concrete work, Fuller and Thompson (1907) suggested that a dense packing of grains can be achieved if the percent finer (p) and grain size (D) are related by the following equation, where n is a constant varying in the range of 0.3-0.6. Dmax is the size of the largest grain within the soil. p=(DDmax)n100 This equation is sometimes used in roadwork for selecting the aggregates. a. For n = 0.5, show that the soil is well graded. b. If n = 0.5 and Dmax = 19.0 mm, find the percentages of gravel, sand, and fines within the soil. Use the Unified Soil Classification System.

Former basketball player Shaquille ONeal weighs approximately 335 lb and wears a size 23 shoe. Estimate the pressure he exerts on a floor. What pressure would he exert if his shoe size were 13? State all your assumptions, and show how you arrived at a reasonable solution.

The results of a tensile test are shown in Table 1.5.2. The test was performed on a metal specimen with a circular cross section. The diameter was 3 8 inch and the gage length (The length over which the elongation is measured) was 2 inches. a. Use the data in Table 1.5.2 to produce a table of stress and strain values. b. Plot the stress-strain data and draw a best-fit curve. c. Compute the, modulus of elasticity from the initial slope of the curve. d. Estimate the yield stress.

The data in Table 1.5.3 were obtained from a tensile test of a metal specimen with a rectangular cross section of 0.2011in.2 in area and a gage length (the length over which the elongation is measured) of 2.000 inches. The specimen was not loaded to failure. a. Generate a table of stress and strain values. b. Plot these values and draw a best-fit line to obtain a stress-strain curve. c. Determine the modulus of elasticity from the slope of the linear portion of the curve. d. Estimate the value of the proportional limit. e. Use the 0.2 offset method to determine the yield stress.

We have used an experimental setup similar to Example 10.1 to determine the value of a spring constant. The deflection caused by the corresponding weights are given in the accompanying table. What is the value of the spring constant? Weight (lb) The Deflection of the Spring (in.) 5.0 0.48 10.0 1.00 15.0 1.90 20.0 2.95