What is the value of the temperature 15 degrees Celsius in degrees Kelvin?

Solve the following quadratic equations:2x² - 4x - 9 = 0 x₊ = 1 + √22/2Answersx_ = 1 - √22/2

Pavel [41]

The root quadratic equation of $2x^{2} - 4x - 9 = 0$ is $x=\frac{2+\sqrt{22}}{2},\:x=\frac{2-\sqrt{22}}{2}$

What is the formula used to calculate the quadratic equation?

To solve the quadratic equation use the formula of $x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

Find the quadratic equation by using the formula ?

On comparing with $2x^{2} - 4x - 9 = 0$

We get , $a=2 , b=-4 , c=-9$

$D=b^{2} +7\\\\\\=(-4)^{2} +7*2*(-9)\\\\=-16-126\\\\=110$

By using the formula,

For a quadratic equation of the form $ax^2+bx+c=0$ the solutions are

$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$X==\frac{-\left(-4\right)\pm \sqrt{\left(-4\right)^2-4\c* \:2\left(-9\right)}}{2\c* \:2}\\\\\sqrt{\left(-4\right)^2-4\cdot \:2\left(-9\right)}\\\\$

Apply rule,

$-(-a)=a\\\\=\sqrt{\left(-4\right)^2+4\cdot \:2\cdot \:9}\\\\$

Apply exponent rule,

$(-a)^{n} =a^{n}$ if n is even

$(-4)^{2} =4^{2}$

$\sqrt{4^2+4\cdot \:2\cdot \:9}$

Multiply the numbers :

$4*2*9=72\\\\\sqrt{4^2+4\cdot \:2\cdot \:9}\\\\4^{2} =16\\\\=\sqrt{16+72}\\\\$

Add the number $=\sqrt{88}$

6 0

1 year ago

A voltage is applied to a resistor,

ladessa [460]

Answer:

Explanation:

By Ohms Law, Voltage = Current * Resistance

Keeping the voltage the same and doubling the resistance, the current will be halved.

So the new current = 1.5/2 = 0.75A

6 0

2 years ago

An airplane travels directly from Washington, D.C., to Atlanta, Georgia, a distance of 850 km at a velocity of 425 km/h southwes

Sloan [31]

Answer:

obviously 2 hours cuz 850/425

Explanation:

4 0

3 years ago

For what angle of incidence at the first mirror will this ray strike the midpoint of the second mirror (which is s=29.0cm long)

Lesechka [4]

The question is missing a diagram of the ray reflection. I attached a diagram which comes from a similar question in the answer section. The full question should be as follows:

Two plane mirrors intersect at right angles. A laser beam strikes the first of them at a point d = 10.0cmfrom their point of intersection, as shown in the figure. For what angle of incidence at the first mirror will this ray strike the midpoint of the second mirror (which is s=29.0cm long) after reflecting from the first mirror?

Answer:

34.6°

Explanation:

To strike the midpoint of the second mirror, the ray light will have to travel half of the distance vertically

i.e. 29/2 = 14.5

We can solve this through trigonometry.

Let the angle between the ray and the vertical plane mirror is known as α

tan α = 10/14.5

α = $tan^{-1} (10/14.5)$ = 34.6°

The angle of incidence is the angle between the ray and the normal line of the mirror.

Let angle of incidence of first mirror be β

β = α = 34.6

6 0

3 years ago

A ball is thrown straight upward and returns to the thrower’s hand after 1.8 s in the air. A second ball is thrown at an angle o

zysi [14]

Answer:

U = 9.1 m/s

Explanation:

from the question we are given the following

time (t) = 1.8 s

angle = 23 degrees

acceleration due to gravity (g) = 9.8 m/s^{2}

let us first calculate the initial velocity (u) which too the first ball to its maximum height from the equation below

v = u + 0.5at

The final velocity (v) is zero since the ball comes to rest

The time (t) it takes to get to the maximum height would be half the time it is in the air, t = 0.5 x 1.8 = 0.9

therefore

0 = u - (0.5 x 9.8 x 0.9)

u = 7.9 m/s

for the second ball to get to the maximum height of the first ball, the vertical component of its initial velocity (U) must be the same as the initial velocity of the first ball. therefore

U sin 60 = 7.9

U = 7.9 ÷ sin 60

U = 9.1 m/s

5 0

3 years ago