A block weighing 30kg is moved at a constant speed over a horizontal surface by a force of 100 N applied parallel

What is the concentration of OH– ions at a pH = 6?

makkiz [27]

<h3><u>Answer;</u></h3>

1 × 10^-8 M

<h3><u>Explanation</u>;</h3>

pH is given by the -log[H+] while

pOH is given by the -log[OH-]

But;

pH + pOH = 14

Thus; if pH is 6, then pOH = 8

pOH = 8

-log[OH-] = 8

[OH-] = 10^-8 M

The concentration of OH- ions at a pH of 6 is 1 × 10^-8 M

8 0

2 years ago

A 19 g bullet is fired into the bob of a ballistic pendulum of mass 1.3 kg. When the bob is at its maximum height, the strings m

katovenus [111]

Answer:

217.43298 m/s

Explanation:

$m_1$ = Mass of bullet = 19 g

$m_2$ = Mass of bob = 1.3 kg

L = Length of pendulum = 2.3 m

$\theta$ = Angle of deflection = 60°

u = Velocity of bullet

Combined velocity of bullet and bob is given by

$v^2-u^2=2as\\\Rightarrow v=\sqrt{2aL(1-cos\theta)+u^2}\\\Rightarrow v=\sqrt{2\times 9.81\times (1-cos60)+0^2}\\\Rightarrow v=3.13209\ m/s$

As the momentum is conserved

$m_1u=(m_1+m_2)v\\\Rightarrow u=\frac{(m_1+m_2)v}{m_1}\\\Rightarrow v=\frac{(0.019+1.3)\times 3.13209}{0.019}\\\Rightarrow v=217.43298\ m/s$

The speed of the bullet is 217.43298 m/s

5 0

3 years ago

What evidence is there that the Universe began in a big bang?<br><br>

NeTakaya

Answer: For me personally i have a Biblical faith and first of all there is evidence that looks convincing that the big bang made the universe, but man wants answers and God in the Bible says he created the universe for us it is hard to believe it but i have faith.

5 0

2 years ago

Read 2 more answers

What do the different colors in a line spectrum represent? why are the spectra for each element unique?

Lana71 [14]

They typically represents different wavelengths of element due to its energy emission in the form of visible light. When an electron of that particular element move from a higher energy level down to a lower energy level, it gives off energy in the form of photon emission. Atom of a certain element has a unique electron arrangement thus it can considered that particular element's spectrum is unique.

8 0

2 years ago

The height of a projectile t seconds after it is launched straight up in the air is given by f (t )equals negative 16 t squared

velikii [3]

Answer:

$\displaystyle a(5)=-32$

Explanation:

<u>Instant Acceleration</u>

The kinetic magnitudes are usually related as scalar or vector equations. By doing so, we are assuming the acceleration is constant over time. But when the acceleration is variable, the relations are in the form of calculus equations, specifically using derivatives and/or integrals.

Let f(t) be the distance traveled by an object as a function of the time t. The instant speed v(t) is defined as:

$\displaystyle v(t)=\frac{df}{dt}$