Engineering Answers

A 1300-kg car is to accelerate from rest to a speed of 30.0 m/s in a time of 12.0s as it climbs a 15.0 hill Assuming uniform acceleration, what minimum horsepower is needed to accelerate the car in this way?

find the volume of the region in the wedge cut from the cylinder x^2+y^2=1 by the planes z=-y and z=0.

A system is taken from state 1 to state 2 along a path A. During this

process it received 200 kJ energy as heat and does 100 kJ work. If the

system is taken from state 2 to state 1 by a different path B, it is necessary

to spend 150 kJ work on the system. Determine the heat interaction along

the path B. Suppose the system is restored to state 1 from state 2 by an

adiabatic path C, how much work has to the done on the system?

The acceleration of gravity is a function of elevation above sea level by

𝑔 = 980.6 − 3.086 × 10−6𝐻

where g is in cm/s2, and H is in cm. If an aeroplane weights 90 kN at sea

level, what is the gravity force upon it at 10,000 m elevation? What is the

percentage difference from the sea-level weight?

A new municipal refuse collection vehicle can be purchased for P84,000. Its expected useful life is 6 years, at which time the Salvage Value (SV) and Book Value (BV) will be zero. Before-tax Cash Flow (BTCF) will be +P18,000 per year over the 6-year life of the vehicle.

a.    Use straight-line (SL) depreciation, an effective income tax rate of 40% and an after-tax MARR of 12% to determine the present worth of the investment.

b.    Is this vehicle a sound investment? Explain your answer.

(A) Stress-strain curves of (1) the metal and (2) the fibers, respectively.

(i)

It is required that the composite containing one type of fiber must have an elastic

modulus no less than 200 GPa, and that the fibers carry no more than 75% of the total

load applied along the longitude direction. Suggest the appropriate type of fiber and

calculate the associated volume fraction.

In a epicyclic gear train an arm carries two gears A and B having 40 and 60 teeth. If arm rotates at 200 rpm in clockwise direction about the centre of gear A which is fixed makes 300 rpm in the anticlockwise direction, what will be the speed of gear B.

6. A closed container contains 2 kg of fluid on a given datum. The container is now raised

vertically 1000m and the fluid is given a velocity of 50 m/s. The work done ON the fluid is 50 kJ

and the heat added is 30 kJ. If the initial internal energy is U 1 = 20 kJ, find U 2 .

A piston-cylinder containing steam at 700 kPaa and 250 o C undergoes a constant pressure process until the quality is 70%. Determine per kilogram.

The falling-rate portion of the drying time for a particle of skim milk begins at a critical moisture content of 25%, and the final moisture content is 4%. The air used for drying is 120 °C was heated from ambient air of 20 °C and 40% RH. The particle size at the critical moisture content is 20 micron, and the specific heat of the product solids is 2.0 kJ/kg °C. The mass diffusivity for water vapor within the product is 3.7´10^-12 m²/s, and the density of the product particle is 1150 kg/m³.

a.   If the equilibrium moisture content for the product is 3.5%, estimate the time for the falling-rate portion of the drying

b.   If 5000 m³/min of heated air are needed for product drying, determine the thermal energy needed to heat the air to 120 °C.