PLEASE HELP ME!!!!!!!

An element is made out of two or more different atoms chemically put together,<br> True<br> Or False

tatyana61 [14]

Answer:

true

Explanation:

it is right

7 0

3 years ago

Jon recently drove to visit his parents who live 648 miles away. On his way there his average speed was 14 miles per hour faster

Vladimir79 [104]

Answer:

speed of the Jon visiting parents = 56 mph

speed of the Jon when returning from home = 56 - 14 = 42 mph

Explanation:

given,

distance of Jon parent's house = 648 mile

avg speed when he was visiting his parent's house be 'x' mph

avg speed when he is returning from his parent's house be 'x-14' mph

total time taken = 27 hours

total distance = speed × time

648 = x × t₁

$t_1 = \dfrac{648}{x}$

648 = ( x - 14 ) × t₂

$t_2 = \dfrac{648}{x-14}$

t = t₁ + t₂

$27 = \dfrac{648}{x} + \dfrac{648}{x-14}$

$1 = 24 (\dfrac{1}{x} + \dfrac{1}{x-14})$

x² - 62 x + 336 = 0

x² - 56 x - 6 x + 336 = 0

(x - 56 )(x - 6)=0

on solving

x = 56 ,6

hence, speed of the Jon visiting parents = 56 mph

speed of the Jon when returning from home = 56 - 14 = 42 mph

8 0

3 years ago

Read 2 more answers

A meter stick has a mass of 0.30 kg and balances at its center. When a small chain is suspended from one end, the balance point

Nata [24]

Answer:

M L1 = m L2 torques must be zero around the fulcrum

M = m L2 / L1 = .3 kg * 28 cm / 22 cm = .382 kg

7 0

3 years ago

The atmosphere has many roles, including:

monitta

There are five layers of the atmosphere and these are; troposphere, stratosphere, mesosphere, thermosphere and exosphere. The first layer, troposphere, is where we are able to do most of our activities. This is where we can see the formation of clouds, the production of rain, hail, snow and other weather phenomenon. Also, this layer is where the greatest amount of air pressure because most of the molecules of air are in this area. Like us, air has also mass and the pressure is brought down by the earth’s gravity causing an increase in weight exerted on you as you descend lower into the atmosphere. So, as you enter into the other layers of atmosphere above the troposphere, the air pressure starts to decrease. <span>Below the atmosphere is the hydrosphere. This is where all liquid forms are located. And since the seawater has a greater mass than air, it has the greatest pressure. </span>

3 0

4 years ago

g The electric field in a sinusoidal wave changes as E =125 N>C2cos 311.2 * 1011 rad>s2t +14.2 * 102 rad>m2x] (a) In wh

Elan Coil [88]

Answer:

a) the propagation direction is x, b) E₀ = 125 N / C² , c) B = 41.67 10⁻⁸ T ,

d) f = 4.95 10¹¹ Hz, e) λ = 4.42 10⁻³ m, f) the speed of light ,

Explanation:

The equation they give for the sine wave is

E = 125 cos (14.2 10² x - 311.2 10¹¹ t)

This expression must have the general shape of a traveling wave

E = Eo cos (kx - wt + Ф)

we can equal each term between the two equations

a) the propagation direction is x, since it is the term that accompanies the vector k

b) the amplitude is the coefficient before the cosine function

E₀ = 125 N / C²

c) to find the amplitude of the magnetic field we use that the two fields are in phase

C = E / B

B = E / c

B = 125/3 10⁸

B = 41.67 10⁻⁸ T

d) the angular velocity is

w = 311.2 10¹¹ rad / s

angular velocity and frequencies are related

w = 2π f

f = w / 2π

f = 311.2 10¹¹ / 2π

f = 4.95 10¹¹ Hz

e) the wavelength is obtained from the wave number

k = 2π /λ

k = 14.2 10² rad / m

λ = 2π / k

λ = 2π / 14.2 10²

λ = 4.42 10⁻³ m

f) the speed of an electromagnetic wave is the speed of light

g) what is a transverse wave

4 0

3 years ago