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2 years ago

15

Si el atomo anterior de litio eléctricamente neutro ¿cuantos electrones deberia tener?

1 answer:

Lubov Fominskaja [6]2 years ago

4 0

Debe ser de tres electrones

You might be interested in

1. Which of the choices will make a brass band?

yuradex [85]

Explanation:

1.

C. Bamboo woodwind instrument

2.

C. Flute

3.

A. Bass Drum

4 0

3 years ago

Given that the efficiency of heating your room is roughly 35%, what mass of natural gas is actually necessary to heat your room

Mrac [35]

Answer:

Mass of natural gas needed to heat the room is 350,000BTUs

Explanation:

The heating efficiency of a furnace is never 100% because not all energy is released and not all heat is available to heat the place. A lesser efficiency requires more consumption of fuel. Heating values are used for heating fuels in order to calculate the mass of fuel needed.

The heating value of natural gas is 1,000,000BTUs

Therefore the formular for calculating mass of natural gas needed= Heating value of natural gas×efficiency.

Mass=1,000,000×0.35

Mass=350,000BTUs

3 0

3 years ago

19) A child on a sled starts from rest at the top of a 15.0° slope. If the trip to the bottom takes 15.2 s,

sveticcg [70]

Answer: 288.8 m

Explanation:

We have the following data:

$t=15.2 s$ is the time it takes to the child to reach the bottom of the slope

$V_{o}=0$ is the initial velocity (the child started from rest)

$\theta=15\°$ is the angle of the slope

$d$ is the length of the slope

Now, the Force exerted on the sled along the ramp is:

$F=ma$ (1)

Where $m$ is the mass of the sled and $a$ its acceleration

In addition, if we draw a free body diagram of this sled, the force along the ramp will be:

$F=mg sin \theta$ (2)

Where $g=9.8 m/s^{2}$ is the acceleration due gravity

Then:

$ma=mg sin \theta$ (3)

Finding $a$ :

$a=g sin \theta$ (4)

$a=9.8 m/s^{2} sin(15\°)$ (5)

$a=2.5 m/s^{2}$ (6)

Now, we will use the following kinematic equations to find $d$ :

$V=V_{o}+at$ (7)

$V^{2}=V_{o}^{2}+2ad$ (8)

Where $V$ is the final velocity

Finding $V$ from (7):

$V=at=(2.5 m/s^{2})(15.2 s)$ (9)

$V=38 m/s$ (10)

Substituting (10) in (8):

$(38 m/s)^{2}=2(2.5 m/s^{2})d$ (11)

Finding $d$ :

$d=288.8 m$

6 0

3 years ago

A 20 g ball of clay traveling east at 4.5 m/s collides with a 45 g ball of clay traveling north at 2.0 m/s. You may want to revi

german

Answer:

The ball travels with a speed of 1.96 m/s in a North East direction

Explanation:

Based on the law of conservation of linear momentum, we have that

$m_{1}v_{1}+m_{2}v_{2}=(m_{1}+m_{2})v$

Since this problem involves motion in both the x and y coordinates, we will solve it in the separate coordinates, and then find the resultant as our answer.

Momentum in the x- direction

in the x direction, $v_{2}= 0$ . this makes $m_{2}v_{2}=0$

hence we have

$20\times4.5=65v_{x}$

$v_{x}=1.385m/s$

Momentum in the y- direction

in the y direction, $v_{1}= 0$ . this makes $m_{1}v_{1}=0$

hence we have

$45\times2.0=65v_{y}$

$v_{y}=1.385m/s$

The resultant of the two vectors can be found using Pythagoras' theorem

$v=\sqrt{1.385^{2}+1.385^{2}} =1.959$

The direction of the resultant vector is found as

$Tan^{-1}(\frac{1.385}{1.385})=45degrees$

Hence the ball moves with a velocity of 1.96m/s in a North East direction

7 0

3 years ago

Why is the power of concave lense negative

Travka [436]

Answer:

because the focal length is negative.

Explanation:

Power of a lens (P) is the reciprocal of its focal length (f).

4 0

3 years ago