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3 years ago

Which of the following is evidence that the universe began with the big bang theory

1 answer:

6 0

<span>There are several main pieces of evidence that support the Big Bang theory. One is the fact that the universe is expanding, proven with something called red shift. The second is something called cosmic microwave background radiation. The third is the abundance of different elements in the universe.

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Jack tries to place magnets on the door of his refrigerator. he observes that the magnets don't stick. he guesses that the door

Tasya [4]

Answer:D

Explanation:

Because u have to make observation then ask a question

3 0

3 years ago

An archeologist on a dig finds a fragment of an ancient

marin [14]

Answer:

19792.96488 years

Explanation:

$\tau_{\dfrac{1}{2}}$ = Half life of carbon-14 atom = 5730 years

Disintegration is given by

$\lambda=\dfrac{ln2}{\tau_{\dfrac{1}{2}}}\\\Rightarrow \lambda=\dfrac{ln2}{5730}\\\Rightarrow \lambda=0.00012\ /years$

The distintegration constant

$0.093N_0=N_0e^{-\lambda t}\\\Rightarrow 0.093N_0=N_0e^{-0.00012 t}\\\Rightarrow ln\dfrac{1}{0.093}=0.00012t\\\Rightarrow t=\dfrac{ ln\dfrac{1}{0.093}}{0.00012}\\\Rightarrow t=19792.96488\ years$

The age of the basket is 19792.96488 years

4 0

3 years ago

What is always included in a comparative investigation?

iragen [17]

A comparison is always included in a comparative investigation. Comparative investigation collects data about different objects, features, organisms, sometimes under a different set of conditions to compare them. The similarities and differences that occur during a set of time or conditions are observed and compared.

4 0

3 years ago

Read 2 more answers

Two appliances are connected in parallel to a 120-v battery and draw currents i1 = 3.0 a and i2 = 3.1

8090 [49]

Initially they are connected in parallel, so they have the same voltage V=120 V at their ends. Therefore we can use Ohm's law to calculate the resistance of each appliance:
$R_1 = \frac{V}{I_1}= \frac{120 V}{3.0 A}=40 \Omega$
$R_2 = \frac{V}{I_2}= \frac{120 V}{3.1 A}=38.7 \Omega$

When they are connected in series, they are crossed by the same current I. The equivalent resistance of the circuit in this case is $R_{eq}=R_1+R_2 = 78.7 \Omega$ , so we can use Ohm's law for the entire circuit to find the current in the circuit:
$I= \frac{V}{R_{eq}}= \frac{120 V}{78.7 \Omega}=1.52 A$

4 0

3 years ago

A 25.0-kg child plays on a swing having support ropes that are 2.20 m long. Her brother pulls her back until the ropes are 42.0°

SCORPION-xisa [38]

(a) 139.7 J

The potential energy of the child at the initial position, measured relative the her potential energy at the bottom of the motion, is

$U=mg\Delta h$

where

m = 25.0 kg is the mass of the child

g = 9.8 m/s^2

$\Delta h$ is the difference in height between the initial position and the bottom position

We are told that the rope is L = 2.20 m long and inclined at 42.0° from the vertical: therefore, $\Delta h$ is given by

$\Delta h = L - L cos \theta =L(1-cos \theta)=(2.20 m)(1-cos 42.0^{\circ})=0.57 m$

So, her potential energy is

$U=(25.0 kg)(9.8 m/s^2)(0.57 m)=139.7 J$

(b) 3.3 m/s

At the bottom of the motion, all the initial potential energy of the child has been converted into kinetic energy:

$U=K=\frac{1}{2}mv^2$

where

m = 25.0 kg is the mass of the child

v is the speed of the child at the bottom position

Solving the equation for v, we find

$v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(139.7 J)}{25.0 kg}}=3.3 m/s$

(c) 0

The work done by the tension in the rope is given by:

$W=Td cos \theta$

where

T is the tension

d is the displacement of the child

$\theta$ is the angle between the directions of T and d

In this situation, we have that the tension in the rope, T, is always perpendicular to the displacement of the child, d. Therefore, $\theta=90^{\circ}$ and $cos \theta=0$ , so the work done is zero.

7 0

3 years ago