A wind turbine has a blade length of 30 m. In a given day, average speed of wind for 5 hours is 9 m/s, average speed of wind for another 9 hours is 11 m/s and wind speed is not sufficient to rotate wind turbine for remaining time in a day. Take Air density p = 1.23 kg/m. Determine the following: a) Maximum possible power output of wind turbine for 6 hours? b) Maximum possible power output of wind turbine for 10 hours? Maximum possible energy output of turbine in a given day?

A tow truck exerts a force of 450 lb. on a car, causing it to accelerate at 10ft/s^2. What is the mass of the car?

1. A new town is being developed in a rural area of Costa Rica. Planners are projecting a population of about 2,000 people and a baseload electric energy demand for the town of 10MWe over the first 20 years. A nearby river flows from the rainforest region with a mean annual flow of 100m³/s. Over a 20 km distance upstream of the town site, the river has a change in elevation of 1,000 m. Seasonal variations in the river flow could be as large as a factor of ten above or below the mean flow. Is a hydro project using turbines with 80% efficiency feasible to meet the town's future energy needs? Discuss (2-3 sentences each) at least two associated impacts that planners also need to consider in the hydro project design.

A water pump increases the water pressure from 15 psia to 90 psia. Determine the powerinput required (hp), to pump 2 ft3/s of water. Neglect potential, heat, kinetic energychanges.

Nhand,A 75 N ma = 3 kg %D VA = 8 m/s Block Block Block Block B A Hx = 0.4 %3D 2 m Ax Note: Diagram is not drawn to scale A hand pushes block A (m,= 3 kg) with a constant force Nand. A= 75 N for a distance Ax 2 m along a (mostly) frictionless table such that it speeds up from rest and is traveling at a speed of 8 m/s after it slides over a rough section of the table (H = 0.4). Block A then collides with a more massive block B (mg = 6 kg) that is initially at rest. Find the speed of block A after it has been released by the hand and just before the rough section of the table. A) 10 m/s B) 20 m/s C) 30 m/s D) 40 m/s E) 50 m/s O A O B O D O E

A well-insulated nozzle has an entrance area of 0.28 m2 and an exit area of 0.157 of m2. Air enters at a velocity of 65 m/s and leaves at 274 m/s. The exit pressure is 101 kPa and the exit temperature is 12°C. a)What is the inlet temperature? b)What is the exit density? c)What is the inlet density? d)What is the inlet Pressure? A V₁=65m $ 0. be P₁ = 101 kPa T₂ = 12°C m V₂=274™ 19 bobivan S

EX.1 An axial flow pump with an impeller rotor diameter of 30 cm handles water at a rate of 2.7 m*/minute running at 1500 rpm. The energy input is K o W 125 J/kg and Total to Total efficiency is 0.75. If a geometrically similar pump has a diameter of 20 cm running at 3000 rpm, find its: i) Flow rate ii) input power.

The steam turbine shown below has a single inlet and two exit streams. It is assumed that the turbine is well insulated and the change in potential energy is negligible. The energy equation governing the turbine based on these assumptions is: OA) B) OD) inlet Turbine J QT - WT=0 C.V. Qr − W₁=m₂ (h + F7)2 +m3 (h+VZ)3-m₂ (h+ QT - Wr=m₂h₂+ m3h3- M₁h₁ w C.V. W₁=m₂ (h+)₁-m₂ (h+)₂ - m₂ (h+)₂