Engineering Answers

A vehicle has a wheel base of 3 m with a centre of gravity 0.8 m above ground level and 1.8 m in front of the rear axle. The coefficient of friction between the wheels and the road is 0.5. The vehicle is traveling horizontally at 90 km/h. Calculate the shortest distance at which the vehicle can be brought to a standstill by means of: 1.1. The brakes on the rear wheels only (14)

1.2. The brakes on both front and rear wheels. 

The velocity field of a flow is given 2 2 V x ti y t x t j m s = + −+ 2 4 ( 1) 2 / ⎡ ⎤ ⎣ ⎦ K JK , where x and y are in meters and t is seconds. For fluid particles on the x axis, determine the speed and direction of flow.

A high-rise tower built by a developer contains 200 condominium units. The QA department of the developer has to approve the tower before turning it over to sales. The QA department will select a random sample of 8 units and inspect them. If more than three major defects are found in any unit, they will reject the unit as defective. If more than 2 of the 8 inspected units are defective, the entire tower will be rejected. If 10 of the 200 units are known to have more than three major defects, what is the probability that the tower will be rejected?

A multi plate clutch has three plates and four pressure plates, pressed together by an axial force of 500N. µ = 0.3. The outer radius of the plates is 100mm, and the inner radius is 80mm. Calculate the torque that the clutch can transmit. If the inner radius and axial force are to remain the same, but the torque is increased by 25%, what must the outer radius than be? (use uniform wear theory)  

An evaporator is used to concentrate 12 000 kg/h of a 15% solution of NaOH entering at 60oC to a product of 50% solid. The pressure of the saturated steam used is 300 kPa and the pressure in the vapour space of the evaporator is 11.7 kPa. The overall heat transfer coefficient is 1 560 W/m2K. Calculate the steam used and the steam economy in kg vaporised/kg steam.

Precalculus

Good day sir could you please assist for solutions to this problems for Precalculus Pre-engineering, which is due today.

*Problem 1*

For the expression

f(x)=log((1-|x|) ÷ (1+|x|))

Determine:

• it's largest domain;

• it's intersections with the x-axis (if any);

• it's intersection with the y-axis (if any);

• it's sign;

• when appropriate, end behaviours and behaviours at accumulation points of the domain which are not in the domain, possible symptoms.

*Problem 2*

Compute, showing the procedure,

limit from x to positive infinity ( square root symbol with x^2 - 3x - square root symbol with x^2 - 5x + 1)

*Problem 3*

Compute, showing the procedure.,

limit from x to negative infinity of the expression (square root with x^6 - x^2)÷(1-2x)

The radius of a circular oil slick on the surface of a pond is increasing at the rate of 10 meters/min. At what rate is the circle's area changing when the radius of the oil slick is 20 m. ?

*Problem1*

f(x) = log((1-|x|)÷(1+|x|))

•It's largest domain

•It's intersections with the x-axis (if any)

•It's intersection with the y-axis (if any)

•It's sign

•when appropriate, end behaviours and behaviours at accumulation points of the domain which are not in the domain, possible asymptotes.

*Problem 2*

Compute, showing the procedure,

limit from x to positive infinity of the problem encircled in brackets ( square root symbol x^2-3x - square root symbolx^2-5x+1)

*Problem 3*

Compute, showing the procedure,

limit from x to negative infinity of the expresion: (square root symbol x^6-x^2)÷(1-2x)