Glass lenses are practically opaque to an emission source with the wavelength shorter than 400nm. (True or False)

Answer:

B

Explanation:

The writers are from a trusted source that is considered impartial. The message is backed up by scientific investigation, and the writers have no monetary gain from their message.

Answer:

25 km/hr

Explanation:

Since Ali's average speed for his trip to school is u = 20 km/hr and his average speed for the return trip to back home from school is v = 30 km/hr, thus his total average speed for the journey is thus V = (initial average speed + final average speed)/2 = (u + v)/2

Substituting the values of the variables into the equation, we have

V = (u + v)/2

V = (20  km/hr + 30 km/hr)/2

V = 50 km/hr/2

V = 25 km/hr

So, the average speed for Ali's trip is 25 km/hr

Answer:

Gravity is a natural phenomenon that causes all massive objects to attract each other. The magnitude or force of this interaction depends on the masses and distance of the bodies. This causes objects to fall toward Earth, for example, and keep satellites and celestial bodies in their orbits, such as the Earth's orbit around the Sun. Gravity also causes the tidal phenomenon.

In physics, gravity can be approximated by Isaac Newton's laws of gravity. Although the accuracy of the law is sufficient, for example, when calculating the orbits of spacecraft, gravity is best described by Albert Einstein’s general theory of relativity, in which it is considered the curvature of space-time.

Answer:

(1) An object that’s negatively charged has more electrons than protons.

(2) An object that’s positively charged has fewer electrons than protons.

(3) An object that’s not charged has the same number of electrons than protons.

Explanation :

Objects have three subatomic particles that are Electrons, protons, and neutrons.

Protons and neutrons are found in the nucleus and electrons rotate or move outside the nucleus. Naturally, protons are positively charged, neutrons have no charge, and electrons are negatively charged.

Therefore, an object that is negatively charged has more electrons than protons.  An object that is not charged has the same number of electrons than protons. An object that is positively charged has fewer electrons than protons.

Answer:

The definition of acceleration is a change in the rate of motion, speed or action.

Acceleration is the rate of change of velocity.

[tex]acceleration = \frac{(final \: velocity - initial \: velocity)}{time} \\ or \\ a = \frac{(v - u)}{t} \\ \\ The \: S.I. \: unit \: of \: acceleration \: is \: \frac{m}{ {s}^{2} } \: or \: m {s}^{ - 2} [/tex].

My last year's notes on acceleration is attached. Hope it helps you!!

Answer:

Yes it would be different on Earth and the moon

Answer:

yes

Explanation:

Answer:

I = 0.2 A

Explanation:

Lamp is rated at 300 mA

I_lamp = 0.3 A

Voltage is; V = 3V

Thus; Resistance is given by;

R = V/I

R = 3/0.3

R = 10 ohms

Now, since the ammeter of 5 ohms is connected in series with the lamp. Thus equivalent resistance;

R_eq = 10 + 5

R_eq = 15 ohms

Ammeter current will be;

I = V/R_eq

I = 3/15

I = 0.2 A

Answer:

The angiosperms dominate Earth's surface and vegetation in more environments, particularly terrestrial habitats, than any other group of plants. As a result, angiosperms are the most important ultimate source of food for birds and mammals, including humans.

Explanation:

plz mark brainlest

Answer:

1) Disolver azúcar en agua - Cambio químico - Es un caso de una solución en donde el solvente es el azúcar y el soluto es el agua.

2) Freir una chuleta - Cambio físico - Es un proceso de cocinado por un transferencia de calor y transferencia de masa.

3) Arrugar un papel - Cambio físico - Se aplica fuerzas externas para deformar el papel.

4) El proceso de la digestión - Cambio químico - Reducción de los alimentos a desechos y la absorción de nutrientes por el contacto con jugos gástricos o ambientes intestinales.

5) Secar la ropa al sol - Cambio físico - El secado es un fenómeno de transferencia de masa.

6) Congelar una paleta de agua - Cambio físico - Cambio del estado líquido al estado sólido por transferencia de calor.

7) Hacer un avión de papel - Cambio físico - Aplicación de fuerzas externas para plegar y doblar la hoja de papel.

8) Oxidación del cobre - Cambio químico - Proceso de corrosión por contacto con iones que se transportan en el ambiente.

9) Romper un lápiz - Cambio físico - Proceso de ruptura por esfuerzo normal a causa de un momento como consecuencia de una fuerza externa aplicada sobre el lápiz.

10) Prender fuegos artificiales - Cambio químico - Reacción química de reducción-oxidación.

11) Excavar un hoyo - Cambio físico - Remoción de tierra por trabajo físico.

12) Quemar basura - Cambio químico - Reacción de combustión.

Explanation:

A continuación, veremos que representa cada caso:

1) Disolver azúcar en agua - Cambio químico - Es un caso de una solución en donde el solvente es el azúcar y el soluto es el agua.

2) Freir una chuleta - Cambio físico - Es un proceso de cocinado por un transferencia de calor y transferencia de masa.

3) Arrugar un papel - Cambio físico - Se aplica fuerzas externas para deformar el papel.

4) El proceso de la digestión - Cambio químico - Reducción de los alimentos a desechos y la absorción de nutrientes por el contacto con jugos gástricos o ambientes intestinales.

5) Secar la ropa al sol - Cambio físico - El secado es un fenómeno de transferencia de masa.

6) Congelar una paleta de agua - Cambio físico - Cambio del estado líquido al estado sólido por transferencia de calor.

7) Hacer un avión de papel - Cambio físico - Aplicación de fuerzas externas para plegar y doblar la hoja de papel.

8) Oxidación del cobre - Cambio químico - Proceso de corrosión por contacto con iones que se transportan en el ambiente.

9) Romper un lápiz - Cambio físico - Proceso de ruptura por esfuerzo normal a causa de un momento como consecuencia de una fuerza externa aplicada sobre el lápiz.

10) Prender fuegos artificiales - Cambio químico - Reacción química de reducción-oxidación.

11) Excavar un hoyo - Cambio físico - Remoción de tierra por trabajo físico.

12) Quemar basura - Cambio químico - Reacción de combustión.

Answer:

Value closest to 1

Explanation:

It is described from the scenario above that ice cream sales decreases as the outside temperature increases, hence showing a strong relationship between both variables (icream sales and temperature). The correlation Coefficient is a metric used in regression modeling to depict the strength of relationship between two variables, (The dependent and independent variables). Correlation Coefficient ranges from (-1 to +1). With values close to 1 or - 1. Also the positive and negative signs are used to show the type of relationship between the variables. If an increase in variable A leads to a decrease in variable B, then we have negative correlation (-) ; while an increase or decrease in both variables depicts a positive correlation. The most likely correlation Coefficient for the study above will be a positive value which is close to 1 since the relationship is described as strong.

Answer:

Determine the direction that the pilot is aiming the plane.

Explanation:

Answer:

displacement

Explanation:

I hope ans will be right

Answer:

A

Explanation:

EDGE22

Answer:

Explanation:

As the ball rises, its PE increases because the potential energy is equal to the mass of the ball times gravity times the height of the ball. The higher the height, the higher the PE.

Answer:

According to the law of conservation of energy its kinetic energy is getting converted in to potential energy because of gain in height. So, if the velocity of a ball goes on decreasing when it is thrown vertically upwards. When its velocity becomes zero, its potential energy becomes maximum.

Answer:

65000g

24.325 hrs

7500m

Answer:

I) 65000 g   II)24.325 hours  III)7500 m

Explanation:

I) 1 kg = 1000 g

65 kg = 65 * 1000 g = 65000 g

II) 1 hour = 3600 seconds

1 second = 1/3600 hours

87570 seconds = 87570 * 1/3600 hours =24.325 hours

III) 1 km = 1000 m

7.5 km = 7.5 * 1000 m = 7500 m

Answer:

10 litres.

Explanation:

The air fuel ratio for aircraft is 12:1. It is due to simplicity piper archer is equipped with continuous flow injection system. There is a fuel sensing is Piper Archer which informs the pilot about the low fuel when the fuel level reaches to as low as 10 litres only in the tank. The yellow low furl light will illuminate to alert the pilot.

Answer:

I = 0.2 A

Explanation:

Lamp is rated at 300 mA

I_lamp = 300 mA = 0.3 A

Voltage is; V = 3V

Thus; Resistance is given by;

R = V/I

R = 3/0.3

R = 10 ohms

Now, since the ammeter of 5 ohms is connected in series with the lamp. Thus equivalent resistance;

R_eq = 10 + 5

R_eq = 15 ohms

Ammeter current will be;

I = V/R_eq

I = 3/15

I = 0.2 A

Answer:

PE = 3.92x10^16J

potential energy

Explanation:

PE = m*g*h

mass of water = 1000kg/m³

(4*10^10m³)*1000kg = 4*10^13kg

PE = (4*10^13kg)*(9.81m/s²)*(100m)

PE = 3.92x10^16J

Answer:

9m is this the way calculator its acceleration

A man is running on the straight road with the uniform velocity of 3 m/s.

Acceleration produced by the man.

Answer:

The Sun on Mars appears two third of the size of the Sun as seen Earth

Explanation:

The distance from the Sun to Mars = 1.5 × The distance from the Sun to Earth

Therefore, compared to the Sun as seen on Earth, we have;

The Sun as seen on Mars = 1.5 × smaller than the Sun as seen on Earth = 2/3 × The size of the Sun as seen on Earth

Answer:

both answer is option C

Explanation:

tag me brainliest

Answer:

The rear wheels of a tractor are very wide so that the weight of the tractor spread over the greatest surface area possible ,so it doesnot sink into the soil.please as brainliest

Explanation:

hope it is helpful to you

Hey there!

Photosynthesis is the reaction that converts light energy to chemical energy in sugar and carbohydrates. Humans can't eat sunlight, so we eat plants. Plants convert the energy in the sunlight into chemical energy using chlorophyll. Chlorophyll is a molecule produced by plants, algae, and cyanobacteria, which aids in the conversion of light energy into chemical bonds. It is the green pigment found in the chloroplasts of higher plants. They are a part of our ecosystem, and they are lower on the food chain.

Hope this helps!

Have a great day! :)

Answer:

  [tex]M = \left[\begin{array}{ccc}cos \ 60&0\\0&-sin \ 60\end{array}\right][/tex]

Explanation:

To find the matrix, let's decompose the vectors, the rotated angle is (-60C) for the prime system

          x ’= x cos (-60)

          y ’= y sin (-60)

we use

          cos 60 = cos (-60)

          sin 60 = - sin (-60)

we substitute

          x ’= x cos 60

          y ’= - y sin 60

the transformation system is

         [tex]\left[\begin{array}{ccc}x'\\y'\end{array}\right] = \left[\begin{array}{ccc}cos 60&0\\0&-sin60\end{array}\right] \ \left[\begin{array}{ccc}x\\y\end{array}\right][/tex]x '

the transformation matrix is

       [tex]M = \left[\begin{array}{ccc}cos \ 60&0\\0&-sin \ 60\end{array}\right][/tex]

Answer:

Physical Changes :- The substance in which no new substance is formed are called physical changes.

The molecular composition of the substance are totally same.

For example :- Crushing a mineral into powder.

Answer:200 Mpa

Explanation:

Given that diameter of cylinder = d = 1-25cm = 1.25 100 =0.0125m

Load or mass = m = Stress 0 = ? 2500kg

Solution: Formula N = F A

Area of Cross-section of cylinder = A=πr2 A = π(d/2) 2

= π(d2/4)

=(3.14)(0.0125)2/4

A = 1.226x10-4

F ・ mg = = F A 24500 2500 x 9.8 = 24500 N

1-226x10-4

1998 36 867.9

= 200 x 106 Pa

= 200 MPa

*Hope it helps you*

Good luck

Answer:

[tex]T=7.5*10^{-5}[/tex]

Explanation:

From the question we are told that:

Radius [tex]r=2cm[/tex]

Work done [tex]W=1.5×10^-4 joules[/tex]

Generally the equation for Work done is mathematically given by

 [tex]W=T.dA[/tex]

Therefore

 [tex]T=\frac{W}{dr}[/tex]

 [tex]T=\frac{1.5*10^{-4}}{2}[/tex]

 [tex]T=7.5*10^{-5}[/tex]

Answer:

a)   t = 20 s,  b)  x = 1000 m, As the runway is only 800 m long, the plane cannot land at this distance

Explanation:

This is a kinematics exercise

a) in minimum time to stop,

           v = vo + at

           v = 0

           t = -v0 / a

we calculate

          t = -100 / (5.00)

          t = 20 s

b) Let's find the length you need to stop

          v² = vo² + 2 a x

          x = -v0 ^ 2 / 2a

          x = - 100² / 2 (-5.00)

          x = 1000 m

As the runway is only 800 m long, the plane cannot land at this distance.

Answer:

The answer is "[tex]1.01 \times 10^{-13}[/tex]"

Explanation:

Using the law of conservation for energy. Equating the kinetic energy to the potential energy.

[tex]KE=U=\frac{kqq'}{r}\\\\[/tex]

Calculating the closest distance:

[tex]\to r=\frac{kqq'}{KE}\\\\[/tex]

[tex]=\frac{k(2e)(79e)}{KE}\\\\=\frac{k(2)(79)e^2}{KE}\\\\=\frac{9.0\times 10^9 \ N \cdot \frac{m^2}{c}(2)(79)(1.6 \times10^{-19} \ C)^2}{(2.25\ meV) (\frac{1.6 \times 10^{-13} \ J}{1 \ MeV})}\\\\[/tex]

[tex]=\frac{9.0\times 10^9 \times 2\times 79\times 1.6 \times10^{-19}\times 1.6 \times10^{-19} }{(2.25 \times 1.6 \times 10^{-13}) }\\\\=\frac{3,640.32\times 10^{-29}}{3.6 \times 10^{-13} }\\\\=\frac{3,640.32}{3.6} \times 10^{-16}\\\\=1011.2 \times 10^{-16}\\\\=1.01 \times 10^{-13}[/tex]

Answer:

A positively charged object moving due west in a region where the Earth's magnetic field is due north experiences a force that is straight down as shown.

A negative charge moving in the same direction would feel a force straight up.