All categories

3 years ago

Which model shows 4 electrons in the outer shell of the atom?

Physics

2 answers:

nasty-shy [4]3 years ago

8 0

D.4
hope it helps have a great day!

EastWind [94]3 years ago

3 0

Answer: d (4)

I think

You might be interested in

A hockey puck is sliding across a frozen pond with an initial speed of 9.5 m/s. It comes to rest after sliding a distance of 37.

Bond [772]

Answer:

<h3>The coefficient of kinetic friction between the puck and the ice is $\mu _{k} =$ 0.12</h3>

Explanation:

Given :

Initial speed $v_{o} = 9.5 \frac{m}{s}$

Displacement $x = 37.4$ m

From the kinematics equation,

$v^{2} - v^{2} _{o} = 2ax$

Where $v^{2} =$ final velocity, in our example it is zero ( $v =0$ ), $a =$ acceleration.

$a =- \frac{90.25}{ 2 \times 37.4}$

$a =- 1.21 \frac{m}{s^{2} }$

From the formula of friction,

$F =- \mu _{k } N$

Minus sign represent friction is oppose the motion

Where $N = mg$ ( normal reaction force )

$ma = -\mu _{k} m g$ ( ∵ $g = 9.8 \frac{m}{s^{2} }$ )

So coefficient of friction,

$\mu_{k} = \frac{1.21}{9.8}$

$\mu_{k} = 0.12$

Therefore, the coefficient of kinetic friction between the puck and the ice is $\mu _{k} =$ 0.12 .

4 0

3 years ago

At a construction site, the site manager notices that a crane takes 20 seconds to lift a 500kg steel beam up to a height of 15 m

posledela

The work done is equal to the change in potential energy which is:
P.E = mgh
P.E = 500 x 9.81 x 15
P.E = 73,575 J

Power = work / time
Power = 73,575 / 20
Power = 3,700 Watts

5 0

4 years ago

An airplane has wings, each with area A, designed so that air flows over the top of the wing at 265 m/s and underneath the wing

exis [7]

Answer

given,

Pressure on the top wing = 265 m/s

speed of underneath wings = 234 m/s

mass of the airplane = 7.2 × 10³ kg

density of air = 1.29 kg/m³

using Bernoulli's equation

$P_1 + \dfrac{1}{2}\rho v_1^2 = P_2 + \dfrac{1}{2}\rho v_2^2$

$\Delta P =\dfrac{1}{2}\rho (v_2^2-v_1^2)$

$\Delta P =\dfrac{1}{2}\times 1.29\times (265^2-234^2)$

$\Delta P =9977.5 Pa$

Applying newtons second law

2 Δ P x A - mg = 0

$A =\dfrac{mg}{2\Delta P}$

$A =\dfrac{7.2\times 10^3 \times 9.8}{2\times 9977.5}$

A = 3.53 m²

7 0

3 years ago

An astronaut named Speedo takes a trip to Sirius, which is located a distance of 8 lightyears from the Earth. If the spaceship m

Softa [21]

Answer:

a. 10 years

b. 6 years

c. 12 years behind

Explanation:

speed of light c = 3x $10^{8}$ m/s

distance of sirius from earth = 8 lightyears = 8 x c x 60 x 60 x 24 x 365 = 252288000c meters

speed of spaceship = 0.8c

time taken to reach sirius = distance covered divided by speed

t = d/s = 252288000c/0.8c = 315360000 sec

1 year = 60 x 60 x 24 x 365 sec = 31536000 sec

315360000 sec = 315360000/31536000 = 10 yrs

the time as observed by Goslo will be shorter than the real time as measured within the ship due to relativistic effects. using the relativistic relation for time dilation we have

t' = t $\sqrt{1 - \frac{v^{2} }{c^{2} } }$

since v = 0.8c

v/c = 0.8

where t' is the relativistic time as observed by Goslo,

t is the time within the ship

t' = 10 x $\sqrt{1 - 0.8^{2} }$ = 6 yrs

If speedo turns around immediately after reaching sirius, his total distance will be 252288000c x 2 = 50457600c meter

time taken = 50457600c/0.8 = 630720000 sec = 20 yrs

time within the ship will be calculated from time dilation

t' = t $\sqrt{1 - \frac{v^{2} }{c^{2} } }$

t' = 20 x $\sqrt{1 - 0.8^{2} }$ = 378432000 sec = 12 years behind

4 0

3 years ago

Use distributive property to express 48+72

Stolb23 [73]

10 ( 6+6 ) = 120

random = abcdefghigklmnopqrstuvwxyz

7 0

3 years ago