Advanced Placement (AP), 02.09.2019 15:30 ianocampo3413

Look at the engine specifications listed below.
4-cylinder in line
displacement = 2.5 liters
dohc 16 valve
140 bhp/7500 rpm
190 foot-lbs/6000 rpm
efi fuel system
compression ratio 8: 1
technician a says the engine described uses a fuel mixture of eight parts air to one part fuel. technician b says the engine described in the figure contains four valves per cylinder. which one of the following statements is correct?
a. neither technician a nor technician b is correct. b. both technician a and technician b are correct. c. only technician a is correct. d. only technician b is correct.

Answers: 1

Show answers

Answers

Answer from: synite

Both Technician A and Technician B are correct. The answer is letter B. Technician A's statement "engine described uses a fuel mixture of eight parts air to one part fuel" is correct because it shows the relationship between air and the fuel ratio. A compression ratio is the ratio of the cylinder volume and the combustion chamber volume when the piston is at the bottom and the combustion chamber volume when it is at the top. Technician B is also correct because for a DOHC cam (double overhead cam) means that there are two valves present at the entrance and exit of gases.

Answer from: Quest

General happiness with the work you do

Answer from: Quest

Answer: the interval on which the curve is concave up is (-∞, -1/2)====== $\displaystyle y = \int_{0}^x \frac{1}{1 + t + t^2} \; dt$ we find the interval where this curve is concave up by finding the interval in which the 2nd derivative is positive.differentiate the curve equation with respect to x $\begin{aligned} \frac{dy}{dx} & = \frac{d}{dx} \int_{0}^x \frac{1}{1 + t + t^2} \; dt \end{aligned}$ let the function f denote be the anti-derivative of the inside expression, i.e. a function such that $(d/dx)f(x) = 1/(1 + t + t^2)$ .then use the fundamental theorem of calculus: $\begin{aligned} \frac{dy}{dx} & = \frac{d}{dx} \int_{0}^x \frac{1}{1 + t + t^2} \; dt \\& = \frac{d}{dx} \big[ f(x) - f(0) \big] & & \text{\footnotesize apply ftc} \\ & = \frac{d}{dx}f(x) - 0 \\ & = \frac{1}{x + x + x^2} & & \text{\footnotesize since $\frac{d}{dx}f(x) = \frac{1}{1 + x + x^2}$ } \end{aligned}$ differentiate again to get second derivative. we can use chain rule with 1/x as the outside function and 1 + x + x² as the inside function $\begin{aligned} \frac{d}{dx} \left( \frac{dy}{dx} \right) & = \frac{d}{dx}\left(\frac{1}{1 + x + x^2} \right) \\ \frac{d^2y}{dx^2} & = \frac{-1}{\left(1 + x + x^2\right)^2} \cdot \tfrac{d}{dx}(1 + x + x^2) \\ & = \frac{-1}{\left(1 + x + x^2\right)^2} \cdot (1 + 2x) \\ & = \frac{-(1 + 2x)}{\left(1 + x + x^2\right)^2} \end{aligned}$ find critical numbers of the second derivative. these numbers are where the 2nd deriv. is undefined or zero.where the 2nd derivative is zero: set (d²y/dx²) to equal 0 and solve for x $\begin{aligned} 0 & = \frac{-(1 + 2x)}{\left(1 + x + x^2\right)^2} \\ 0 & = -(1+2x) \\ -1 & = 2x \\ x & = -1/2 \end{aligned}$ where the 2nd derivative is undefined: if the denominator is equal to zero, the derivative will be undefeined. attempting to solve the equation 1 + x + x² = 0results in a discriminant of $b^2 - 4ac = 1^2 - 4(1)(1) = -3$ meaning that the equal 1 + x + x² = 0 has no real solutions and therefore will never equal zero.======our only critical number is x = -1/2.this forms two intervals to test the sign for: (-∞, -1/2) and (-1/2, ∞)test values into the 2nd derivative for (-∞, -1/2)if we try x = -1, we get $\begin{aligned} \left.\frac{d^2y}{dx^2}\right|_{x = -1} & = \frac{-(1+2(-1))}{\left(1+(-1)+(-1)^2\right)^2} \\ & = \frac{-(1-2)}{1} \\ & = 1 \end{aligned}$ so the since the 2nd derivative of the curve is positive on the interval (-∞, -1/2), the curve is concave up on (-∞, -1/2)test values into the 2nd derivative for (-1/2, ∞)if we try x = 0, we get $\begin{aligned} \left.\frac{d^2y}{dx^2}\right|_{x = 0} & = \frac{-(1+2(0))}{\left(1+(0)+(0)^2\right)^2} \\ & = \frac{-(1)}{1} \\ & = -1 \end{aligned}$ so the since the 2nd derivative of the curve is positive on the interval (-∞, -1/2), the curve is concave down on (-∞, -1/2).the interval on which the curve is concave up is (-∞, -1/2)

Another question on Advanced Placement (AP)

Advanced Placement (AP), 24.06.2019 01:00

What did executive order 9981 accomplish

Answers: 1

Answer

Advanced Placement (AP), 24.06.2019 04:00

Brian has been working for a few years now and has saved a substantial amount of money. he now wants to invest 50 percent of his savings in a bank account where it will be locked for three years and gain interest. which type of bank account should brian open?

Answers: 2

Answer

Advanced Placement (AP), 25.06.2019 13:30

Compare and contrast the impact of global commerce on european and asian dynasties. did any dynasty hold an advantage over others in controlling commercial networks and using them to enrich their societies?

Answers: 1

Answer

Advanced Placement (AP), 26.06.2019 14:10

Afunction g(x) is defined as shown.a function g(x) is defined as shown. what is the value of g(4)?

Answers: 1

Answer

You know the right answer?

Look at the engine specifications listed below.
4-cylinder in line
displacement = 2.5 l...

Questions