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2 years ago

Which phrase describes an atom?

1 answer:

4 0

<span>a negatively charged electron cloud surrounding a positively charged nucleus, the third one is the right answer.</span><span>

Nucleus consists of e</span>lectrically neutral neutrons and positively charged protons, so it is positively charged. Electrons, on the other hand are negatively charged. Electromagnetic force bounds atoms to the nucleus.

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01 – (Valor – 2,0) O maior campo de testes de veículos da América Latina, localizado na cidade de Indaiatuba (SP), tem forma cir

Scilla [17]

Answer:

a) Calcule a frequência em RPM

= 0.6 RPM

b) a velocidade escalar do carro em m/s.

= 20m/s

Explanation:

a) Calcule a frequência em RPM

A fórmula para calcular a frequência é: 1/T

onde T= Tempo (seconds)

T = 100s

A frequência = 1/100s

A frequência = 0.01Hz

em RPM

A fórmula para calcular a frequência em RPM =

1 Hz = 60RPM

0.01Hz =

A frequência em RPM = 0.01Hz × 60

= 0.6 RPM

b) a velocidade escalar do carro em m/s.

A fórmula para calcular a velocidade escalar = diâmetro ou distância (m) ÷ tempo (s)

Diâmetro ou Distância = 2.0km

Converter 2.0km para m

1 km = 1000m

2km =

2 km × 1000m

= 2000m

A velocidade escalar = 2000m ÷ 100s

A velocidade escalar = 20m/s

Answer:

a) Frequency in RPM

= 0.6 RPM

b) Scalar Velocity

= 20m/s

Explanation:

a) Frequently in RPM

Formula : 1/T

Where T= Time (seconds)

T = 100s

= 1/100s

= 0.01Hz

Frequency in RPM =

1 Hz = 60RPM

0.01Hz = 0.01Hz × 60

= 0.6 RPM

b) Scalar velocity

The formula = Diameter or Distance ÷ Time

Diameter or Distance = 2.0km

Convert 2.0km to m

1 km = 1000m

2km =

2 km × 1000m

= 2000m

Scalar Velocity = 2000m ÷ 100s

Scalar Velocity = 20m/s

8 0

2 years ago

A woman is applying 300N/m2 of pressure on to door with her hand. Her hand has area of 0.02m2. Work out the force being applied

never [62]

Answer:

Explanation:

Given parameters:

Pressure applied by the woman = 300N/m²

Area = 0.02m²

Unknown:

Force applied = ?

Solution:

Pressure is the force per unit area on a body

Pressure = $\frac{force}{area}$

Force = Pressure x area

Force = 300 x 0.02 = 6N

8 0

2 years ago

89. An electron is moving in a straight line with a velocity of 4.0×105 m/s. It enters a region 5.0 cm long where it undergoes a

ddd [48]

Explanation:

Given that,

Initial speed of the electron, $u=4\times 10^5\ m/s$

Distance, s = 5 cm = 0.05 cm

Acceleration of the electron, $a=6\times 10^{12}\ m/s^2$

(a) Let v is the electron's velocity when it emerges from this region. It can be calculated as :

$v^2=u^2+2as$

$v^2=(4\times 10^5)^2+2\times 6\times 10^{12}\times 0.05$

v = 871779.788 m/s

$v=8.71\times 10^5\ m/s$

(b) Let t is the time for which the electron take to cross the region. It can be calculated as:

$t=\dfrac{v-u}{a}$

$t=\dfrac{8.71\times 10^5-4\times 10^5}{6\times 10^{12}}$

$t=7.85\times 10^{-8}\ s$

Hence, this is the required solution.

4 0

2 years ago

An experiment is designed to test what color of light will activate a photoelectric cell the best. The photocell is set in a cir

Natalija [7]

A photoelectric cell is an electronic device which is used to convert light energy into electric energy.The operation of this device is based on photoelectric effect.

Light of suitable frequency i.e greater or equal to threshold frequency will fall on the cathode maintained at negative potential.The electron emission will take place and these electrons are drifted towards the anode which is at positive potential.

Here,only those radiations will be capable of emitting electrons irrespective of surface barrier of metals whose energy is greater than the work function.

We know that the radiation having long wavelength has least energy as energy and wavelength are inversely proportional to each other.

$Mathematically\ energy\ E=\frac{hc}{\lambda}$

Here h is the Planck's constant,c is the velocity of light.

Here we have been given red light and blue light.

In the visible spectrum of radiation, the red light has longer wavelength than all other colors of light.Hence blue light has more energy as it's wavelength is less as compared to red light.

Hence, the blue light will activate the most and red the least.

3 0

2 years ago

Read 2 more answers

Water is contained in a closed, rigid 0.2 m 3 tank at an initial pressure of 5 bar and a quality of 50%. Heat transfer occurs un

elena55 [62]

Answer:

Final mass=0.89kg

Final pressure=5.6bar

Explanation:

To find mass,m=v/v1

But v1=vf + x(vg-vf)

Vf= 0.001093m^3/kg

Vg= 0.3748m^3/kg

V1= 0.001093+0.5(0.3748-0.001093)

V1= 0.225m^3/kg

M= 0.20/0.225 =0.89kg

Final pressure will be:

V/V1= P/P1

Cross multiply

VP1=V1P

P1= 0.225×5/0.2

P1=:5.6 bar

7 0

2 years ago