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2 years ago

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Ancient Greek philosophers were the first to discuss atoms and matter. This became known in time as____________. Atomic theory s

tates that matter is composed of ____________ units called atoms.

1 answer:

Vedmedyk [2.9K]2 years ago

6 0

Answer:

atoms,

Explanation:

sorry don't know the second answer

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A simple generator is used to generate a peak output voltage of 19.0 V . The square armature consists of windings that are 6.65

salantis [7]

One of the efficient concepts that can help us find the number of turns of the cable is through the concept of induced voltage or electromotive force given by Faraday's law. The electromotive force or emf can be described as,

$\epsilon = NBA\omega$

Where,

N = Number of loops

B = Magnetic Field

A = Cross-sectional Area

$\omega$ = Angular velocity

Re-arrange to find N,

$N = \frac{\epsilon}{BA\omega}$

Our values are given as,

$\epsilon = 19V$

$B = 0.434T$

$\omega = 49.8\frac{rev}{s} (\frac{2\pi rad}{1 rev}) = 99.6\pi rad/s$

$A = (6.65*10^{-2})^2 m^2$

Replacing at our equation we have:

$N = \frac{\epsilon}{( 0.434)A\omega}$

$N = \frac{19}{( 0.434)((6.65*10^{-2})^2)(99.6\pi)}$

$N = 31.63 \approx 32$

Therefore the number of loops of wire should be wound on the square armature is 32 loops

6 0

3 years ago

I need help fast please help

Irina18 [472]

A and C Im pretty sure :)

5 0

3 years ago

The line graph below shows the number of downloads of two songs after

daser333 [38]

Answer: D

1200

Explanation:

Song 1 is spotted with a cube sign.

At 3 minute, trace the spot to the vertical axis. And you will notice that it a little bit above 10.

Since it is above 10, let assume it is equal to 12.

The number of song downloaded are in hundreds. Therefore, multiply the 12 by 100

12 × 100 = 1200 downloads

Approximately, song 1 has 1200 downloads at minute 3

5 0

3 years ago

A sled that has a mass of 8 kg is pulled at a 50 degree angle with a force of 20 N. The force of friction acting on the sled is

vitfil [10]

The acceleration of the sled will be 1.30 m/s². Force is defined as the product of mass and acceleration.

<h3>What is force?</h3>

Force is defined as the push or pulls applied to the body. Sometimes it is used to change the shape, size, and direction of the body.

Given data;

m(mass of sled)=8 kg

Θ is the inclination of force= 50°

Force of friction,f=2.4 N.

The applied force at the given angle is resolved into the two-component as;

$\rm F_h=F cos \theta \\\\ F_h= 20 cos 50 ^0 \\\\ F_h= 12.85 \ N$

$\rm F_v=F sin \theta \\\\ F_v=20 sin 50^0 \\\\ F_v=15.32 \ N$

The net vertical force is zero;

$\rm F_N=mg-Fsin50^0 \\\\ \rm F_N=8 \times 9.81 -15.32 \\\\ F_N=63.1 \ N \\\\$

From Newton's second law the net force as;

$\rm \sum F_{net}=ma \\\\ Fcos 60^0-f =ma \\\\ a=\frac{12.855-2.4}{8} \\\\a = 1.30 \ m/s^2$

Hence, the acceleration of the sled will be 1.30 m/s².

To learn more about the force refer to the link;

brainly.com/question/26115859

#SPJ1

5 0

2 years ago

Read 2 more answers

a person throws a ball upward into the air with an initial velocity of 20 m/s. calculate (a) how high it goes, and (b) how long

Phantasy [73]

Answer:

a) about 20.4 meters high

b) about 4.08 seconds

Explanation:

Part a)

To find the maximum height the ball reaches under the action of gravity (g = 9.8 m/s^2) use the equation that connects change in velocity over time with acceleration.

$a=\frac{Vf-Vi}{t}$

$-9.8 \frac{m}{s} =\frac{Vf-Vi}{t}$

In our case, the initial velocity of the ball as it leaves the hands of the person is Vi = 20 m/s, while thw final velocity of the ball as it reaches its maximum height is zero (0) m/s. Therefore we can solve for the time it takes the ball to reach the top:

$-9.8 =\frac{0-20}{t}\\t=\frac{20}{9.8} s = 2.04 s$

Now we use this time in the expression for the distance covered (final position Xf minus initial position Xi) under acceleration:

$Xf-Xi=Vi*t+\frac{1}{2} a t^{2} \\Xf-Xi=20*(2.04)-\frac{1}{2} 9.8*2.04^{2}\\Xf-Xi=20.408 m$

Part b) Now we use the expression for distance covered under acceleration to find the time it takes for the ball to leave the person's hand and come back to it (notice that Xf-Xi in this case will be zero - same final and initial position)

$Xf-Xi=0=20*(t)-\frac{1}{2} 9.8*t^{2$

To solve for "t" in this quadratic equation, we can factor it out as shown:

$0= t(20-\frac{9.8}{2} t)$

Therefore there are two possible solutions when each of the two factors equals zero:

1) t= 0 (which is not representative of our case) , and

2) the expression in parenthesis is zero:

$0= 20-\frac{9.8}{2} t\\t=\frac{20*2}{9.8} = 4.08 s$

7 0

3 years ago