Civil and Environmental Engineering Answers

Find the equation of the hyperbola with center (4, - 1), transverse axis parallel to the Y-axis, distance between foci 10, latus rectum 9/2.

Differentiate derivative of transforms and transforms of derivatives

A spring is such that a 2 lb weight stretches it by 6 in. There is a damping force present, with

the magnitude equal to 0.75|𝑣|. An impressed force of F(t) = 2 sin 8t is acting on the spring. If

the 2-lb weight is released from a point 3 in below the equilibrium point, describe the motion

A spring is such that a 4 lb weight stretches it by 0.64 ft. The weight is pushed up 1/3 ft above

the equilibrium point and started with an initial downward velocity of 5 ft/sec. The motion takes

place in a medium which furnishes a damping force of magnitude 0.25|𝑣| at all times. Describe

the motion.

A spring is such that it would be stretched 8 in by a 4 lb weight and a damping force of

magnitude 0.5|𝑣| is added because of immersing the body in a thick liquid. Let the weight be

attached to a spring and pulled down 5 in below the equilibrium point. If the weight is started

with an upward velocity of 3.5 flt/sec, describe the motion. No impressed force is present.

what is the significance of partial fractions to laplace transforms

differentiate derivatives of transform and transforms of derivatives

Why is it important to have

different Decision Analysis Models?

Tom Jackson is buying a new car. Alternative A is an American-built compact. It has an initial cost of

$8900 and operating costs of 9cents /km, excluding depreciation. From resale statistics, Tom estimates

the American car can be resold at the end of 3 years for $1700.Alternative B is a foreign-built Fiasco.

Its initial cost is $8000, the operating cost, also excluding depreciation, is 8 cents /km. How low could

the resale value of the Fiasco be to provide equally economical transportation? Assume Tom will drive

12,000 km/year and considers 8% as an appropriate interest rate.

A road between Fairbanks and Nome, Alaska, will have a most likely construction cost of $4 million per

mile. Doubling this cost is considered to have a probability of 30%, and cutting it by 25% is considered

to have a probability of 10%. The state’s interest rate is 8%, and the road should last 40 years. What is

the probability distribution of the equivalent annual construction cost per mile?