A machine can never be 100% efficient because some work is always lost due to which factor?
A.friction
B.gravity
C.static
D.input force

Answer:

1:281.25m

2:75m/s

Explanation:

using the equation

[tex]v^{2} = u^{2} + 2gs[/tex]

at maximum height v is zero so using that you can make s the subject of the formula

[tex]h \: max = u^{2} \div \: 2g[/tex]

so substitute the velocity 75 and the constant g-10m/s^2

as for the returning velocity we say displacement is zero since you go and come back the same distance

so

[tex]v = { + or - }u[/tex]

u is the initial speed in this case it's positive since going in the direction of gravity

Answer:

Take a look at the attachment below.

Explanation:

Current for each branch of the circuit is 2A and equivalent resistance of the circuit will be 5 ohms. The current through the battery is 6A.

An electric current is defined as a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space, which is described as the flow of electric charge through a surface or in a control volume.

Current is expressed as:

I=V/R

Where, I is the current

V is the voltage

R is the resistance

For above given information,

Since all resistors have the same resistance, it would be fine to find only 1 branch as the current would be the same for all branches.

[tex]I=V/R_1[/tex]

I= 30/15= 2 A

Equivalent resistance for parallel circuits is the sum of reciprocals of each resistor.

[tex]1/R= 1/R_1+ 1/R_2+ 1/R_3[/tex]

1/R= 1/15+ 1/15 + 1/15

1/R=3/15

R = 15/3= 5 ohms

I = V/R

Where I is current, V is voltage and R is the equivalent resistance

=> I = 30/5

=> I = 6 A

Thus, current for each branch of the circuit is 2A and equivalent resistance of the circuit will be 5 ohms. The current through the battery is 6A.

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Answer:

A) OA, AB, BC

B) 25m/s^2

C) see explanation

D) 25

E) Rest

Explanation:

From the Velocity time graph shown:

The positive slope = OA ; This is positive because, it is the point of uniform acceleration on the graph.

Constant slope = AB, the slope here is constant because, AB on the graph is the point of constant velocity.

-ve slope = BC

B) Acceleration of body in path OA.

Acceleration = change in Velocity / time

Acceleration = (150 - 0) / 6

Acceleration = 150/6 = 25m/s^2

C) Path AB is Parallel to the because it marks the period of constant velocity (that is Velocity does not increase or decrease during the time interval).

D) Length of BC

BC corresponds to the distance moved, that velocity / time

Velocity = 150 ; time = 6

Therefore Distance (BC) = 150/6 = 25

E.) Velocity =0 ; Hence body is at rest

Answer:

The impacts of modern communication in our socio economic life includes;

a) Staying connected

b) Carrying out business transaction

c) Exceeding boundaries

d) Overcoming weakness and disability

e) Reaching out to a wider audience

2. It is possible to make long distant call to our relatives in other part of the country by direct distance dialing (DDD)

Explanation:

The telecommunication service called direct distance dialing allows a caller to make a call to a location outside the area where they are calling without the assistance of an operator. To make a direct dialing call, a subscriber or caller will be required to include extra prefix digits to the original number than for numbers within hers or his particular local area code.

Answer:

A) F_g = 8.9278 × 10^(-30)

B) F_e = 1.6 × 10^(-17) N upwards

C) F_m = 6.8 × 10^(-17) N downwards

Explanation:

A) Formula for gravitational force is;

F_g = m_e × g

m_e is mass of electron = 9.11 x 10^(-31) kg

F_g = 9.11 x 10^(-31) × 9.8

F_g = 8.9278 × 10^(-30) N downwards

B) Formula for Electric force is;

F_e = qe

q is charge on electron = 1.6 × 10^(-19) C

E is electric field = 100 N/C

F_e = 1.6 × 10^(-19) × 100

F_e = 1.6 × 10^(-17) N upwards

C) Magnetic force is given by the formula;

F_m = qVB

q is charge on electron = 1.6 × 10^(-19) C

V is velocity given as 8.50 × 10^(6) m/s

B is magnetic field = 50.0 μT = 50 × 10^(-6) T

F_m = 1.6 × 10^(-19) × 8.50 × 10^(6) × 50 × 10^(-6)

F_m = 6.8 × 10^(-17) N downwards

Answer: C.) Neptune

Explanation:

The Gravitational Potential Energy (GPE) of a body is calculated using the formula :

GPE = mgh

Where m = mass of the body

g = acceleration due to gravity

h = distance above a surface

Mass = 10kg

h = 2m

Using the formula :

GPE of lamp on Earth: g = 9.8

GPE = 10 × 9.8 × 2 = 71.8J

GPE of lamp on Mercury: g = 3.59

GPE = 10 × 3.59 × 2 = 196J

GPE of lamp on Mars: g = 3.7

GPE = 10 × 3.7 × 2 = 74J

GPE of lamp on Neptune: g = 14.07

GPE = 10 × 14.07 × 2 = 281.4J

GPE of lamp on Uranus: g = 9

GPE = 10 × 9 × 2 = 180J

GPE of lamp on Pluto: g = 0.42

GPE = 10 × 0.42 × 2 = 8.4J

Neptune has the highest gravitational potential energy as the value of acceleration due to gravity acting on objects is highest on Neptune.

Answer:

The correct option is;

C) Neptune

Explanation:

The force of gravity is given by the equation;

[tex]F_g = G\dfrac{m_1m_2}{r^2} = m_2 \times g[/tex]

Where:

m₁ = Mass of the planet

m₂ = Mass of the body = 10 kg

r = The distance between the body and the planet = 2 m

g = Gravitational acceleration on the planet

G = Gravitational constant

Given that the potential energy, PE = m × g × h

We have that,

[tex]PE = m_2 \times g \times (r + 2) = G\dfrac{m_1m_2}{r^2} \times (r + 2) \approx G\dfrac{m_1m_2}{r^2} \times r = G\dfrac{m_1m_2}{r}[/tex]

Therefore, the gravitational potential energy is directly proportional to the acceleration of gravity, such that the body will have the most gravitational potential energy in the planet with the highest acceleration due to gravity which is Neptune with acceleration due to gravity of 14.07 m/s².

Answer:

The weight of barbell acting on a weight lifter is 80N.

Explanation:

Answer:

Direct current

Explanation:

Answer:

Light from star would take 100 years to reach the Earth.

Explanation:

1 light year = speed of light × 1 year

1 light year = 9.46 × 10¹⁵ m

hope i helped

-lvr

Answer:

a

Explanation:

;)

Answer:

8.43 m/s²

Explanation:

Average acceleration is the change in velocity over change in time.

a = Δv/Δt

First, convert km/h to m/s.

45 km/h = 12.5 m/s

500 km/h = 138.9 m/s

Now find the acceleration.

a = (138.9 m/s − 12.5 m/s) / 15.0 s

a = 8.43 m/s²

Answer:Deforestation refers to the decrease in forest areas across the world that are lost for other uses such as agricultural croplands, urbanization, or mining activities. Greatly accelerated by human activities since 1960, deforestation has been negatively affecting natural ecosystems, biodiversity, and the climate. The UN’s Food and Agriculture Organization estimates the annual rate of deforestation to be around 1.3 million km2 per decade.

Explanation:

The negative effect of deforestation on the environment is desertification. The correct option is B.

Desertification is the process by which fertile land becomes desert, typically as a result of drought, deforestation, and inappropriate agriculture or land use practices. It occurs when land that was once able to support vegetation and life becomes increasingly dry, barren, and unable to sustain crops, livestock, or human populations. This can be due to natural causes such as prolonged droughts, but it is often exacerbated by human activities such as deforestation, overgrazing, and soil degradation. Desertification can have devastating effects on the environment, leading to soil erosion, loss of biodiversity, and reduced productivity of the land. It can also cause social and economic problems, such as displacement of people, food shortages, and conflicts over resources.

Here in the question,

Deforestation is the clearing of trees and other vegetation from an area, leading to the loss of habitat and biodiversity, and disruption of water cycles. It can also cause soil erosion, which can result in the depletion of soil nutrients, reduced productivity, and eventually lead to desertification. Additionally, deforestation contributes to climate change by releasing carbon dioxide into the atmosphere, which can cause global warming and other environmental problems. Habitat restoration, soil production, and urbanization are not negative effects of deforestation but can be impacted by it.

Therefore, The correct answer is B i. e Desertification.

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The two resistors in parallel behave like 3 ohms.

I = V / R

Current = 12/3 = 4 Amps

Answer:

The correct option is;

Hire an environmental company to study the wetland and give recommendations of how to prevent flooding

Explanation:

Due to the environmental importance of wetlands which are important plant and animal habitats and a source of filtration of reserve of water moving into other surface water bodies and underground aquifers, serving also as a buffer zone to prevent erosion and flooding during heavy rain storms, proper, detailed and well informed environmental considerations are required

As such an environmental consultant services is needed for site analysis, appraisal and recommendation will be required to fast track the process of obtaining a permit.

Answer:

A

Explanation:

Answer:

Horizontal component = 241 N

Vertical component =  287 N

Explanation:

Given:

Force =  F = 375 N

Referring to diagram attached, the force F is making an angle

theta = 20+30 = 50 with the horizontal.

Horizontal component = F*cos(theta) = 375*0.64278 = 241 N

Vertical component = F*sin(theta) = 375*0.76604 = 287 N

The vertical component of the force is  187.5 N  and the horizontal component of the force is  324.8 N.

A vector is a any quantity that has both magnitude and direction. We can resolve any vector into its vertical and horizontal components. The vertical component of a vector such as force is F sin θ while the horizontal component of the force is F cos θ.

Given the following information from the question;

F =  375 N

θ = 30.0°

Vertical component(Fy) = 375 N sin 30.0° = 187.5 N

Horizontal component (Fx) = 375 N cos 30.0° = 324.8 N

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Answer:

Part A:

They will repel each other because same poles repel each other.

Part B)

They will attract each other because different poles attract each other..

Answer:

Writing of a story that ends with the character becoming poor with no friends.

Explanation:

There was a young girl who believed that all things revolve around her. She had the money, the power, the family, and the beauty to ensure she was the center of attention. She would always be the main focus, everywhere she goes.

But there came a time when she had a major misfortune. Her family had come upon unfortunate times. They are going to lose their money and may even be jailed for embezzlement. It was true that she had no idea what her parents had done but she was also so familiar with the 'princess' lifestyle that she did not know how to downgrade her lifestyle. And so, when this misfortune happened, she was unsure how to react. She also assumed that her friends will be there for her. Little did she know everyone was just after her wealth and influence and had nothing to do with genuine friendship.

In a few months, their family position moved from top to bottom, which everyone found hard to accept. She had to maintain her status while at the same time try to live up with that without losing her circle. But as rumors spread fast and she wasn't able to spend the way she would normally send, she eventually experienced a dwindled friend circle. And in about a year, she had lost all of her friends, couldn't even convince someone to stay with her faithfully and worse of all, she was also poor, the very status she had degradingly taunted other people with.

Answer:

Índice de refracción entre los dos medios = 1,43

Refractive index between the two media = 1.43

Explanation:

El índice de refracción entre dos medios se explica mejor entendiendo primero la refracción.

Cuando las olas se mueven de un medio a otro, a menudo experimentan un cambio de dirección con respecto al medio en el que viajan.

Por lo tanto, el índice de refracción se expresa como el seno del ángulo de incidencia dividido por el seno del ángulo de refracción.

El seno del ángulo de incidencia y la refracción utilizados en esta fórmula de índice de refracción se miden respectivamente con respecto a la vertical.

En esta pregunta Ángulo de incidencia = 35° a la horizontal = (90° - 35°) a la vertical = 55° a la vertical.

Ángulo de refracción = 35°

Índice de refracción entre los dos medios

= (Sin 55°) ÷ (Sin 35°)

= 0.8192 ÷ 0.5736

= 1.428 = 1.43 a 2 d.p.

¡¡¡Espero que esto ayude!!!

English Translation

The light passes from medium A to medium B at an angle of 35 ° with the horizontal border between the two. If the angle of refraction is also 35 °, what is the relative refractive index between the two media?

Solution

The refractive index between two media is best explained by first understanding refraction.

When waves move from one medium to another, they often experience a change in direction with respect to the medium in which they are travelling.

Hence, refractive index is expressed as the sine of angle of incidence dibided by the sine of angle of refraction.

The sine of angle of incidence and refraction used in this refractive index formula are both respectively measured with respect to the vertical.

In this question,

Angle of incidence = 35° to the horizontal = (90° - 35°) to the vertical = 55° to the vertical.

Angle of refraction = 35°

Refractive index between the two media

= (Sin 55°) ÷ (Sin 35°)

= 0.8192 ÷ 0.5736

= 1.428 = 1.43 to 2 d.p.

Hope this Helps!!!

Answer:

Short sight occurs when the eyeball is too long or the lens is too thick, or both. As a result, light rays from distant objects are focused in front of the retina (because the light rays are highly converged). The image formed on the retina is therefore out of focus.

Short sight can be corrected by wearing glasses with concave lenses. Light rays from distant objects are diverged by concave lenses before entering the eyes, so that light can be focused on the retina to form a sharp image.

Answer:

v = 3.24 m/s

Explanation:

Since we don't have time, we can use the formula;

(Final distance - initial distance)/time = (initial velocity + final velocity)/2

Thus;

(x_f - x_i)/t = ½(v_xi + v_xf)

We are given;

x_i = 0 m

x_f = 5 m

v_xi = 0 m/s

v_xf = 5 m/s

Thus, plugging in the relevant values;

(5 - 0)/t = (0 + 5)/2

5/t = 5/2

t = 2 s

Using Newton's first law of motion, we can find the acceleration.

v = u + at

Applying to this question;

5 = 0 + a(2)

5 = 2a

a = 5/2

a = 2.5 m/s²

To get the speed, in m/s, of the block when it had traveled only 2.1 m from the top, we will use the formula;

v² = u² + 2as

v² = 0² + 2(2.5 × 2.1)

v² = 10.5

v = √10.5

v = 3.24 m/s

Answer:

Sound travels fastest through solids. This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it. In fact, sound waves travel over 17 times faster through steel than through air.

Answer:

Explanation:

Check the complete diagram n the attachment below

a) The angle of incidence on a plane surface is the angle between the incidence ray and the normal ray acting on a plane surface. The normal ray is the ray perpendicular to the surface while the incidence ray is the ray striking a plane surface.

According to the diagram, the angle of reflection r₂ on M₂ is 90°-g where g is the angle of glance.

Given angle of glance on M₂ to be 40°, r₂ = 90-40 = 50°

According the second law of reflection, the angle of incidence = angle of reflection, therefore i₂ = r₂ = 50° (on M₂)

Also ∠OO₂O₁ =  ∠OO₁O₂ = 40° (angle of glance on M₁){alternate angle}

The angle of incidence on M₁ = 90° - 40° = 50°

b) The angle of incidence to the surface of M₁(∠PO₁A)will be the angle of glance on M₁ which is equivalent to 40°

Answer:

The two forms of energy that increase during the time after take off are;

1) The kinetic energy KE

1) The potential energy PE

Explanation:

1) Given that the airplane is accelerating, we have that the velocity, v, of the airplane is increasing, such that the we have the kinetic energy, KE, for a given mass, m, of the airplane increasing as follows;

KE₂ = 1/2×m×v₂² > KE₁ = 1/2×m×v₁²

2) Also, as the height, h, of the airplane increases during the ascent, we have that the potential energy increasing along side as follows;

PE₂ = m × g × h₂ > PE₁ = m × g × h₁

Therefore, the two forms of energy that increase during the time after take off are the kinetic  and the potential  energy.

Answer:

79%

Explanation:

Data obtained from the question include the following:

Input temperature = 100°C

Output temperature = 22°C

Efficiency =.?

Next, we shall convert celsius temperature to Kelvin temperature.

This is illustrated below:

T(K) = T (°C) + 273

Input temperature = 100°C

Input temperature in Kelvin = 100°C + 273 = 373K

Output temperature = 22°C

Output temperature in Kelvin = 22°C + 273 = 295K

Finally, we shall determine the efficiency of the locomotive as follow:

Efficiency = output /input x 100

Output = 295K

Input = 373K

Efficiency =?

Efficiency = output /input x 100

Efficiency = 295/373 x 100

Efficiency = 79%

Therefore, the efficiency of the locomotive is 79%.

Answer:

The answer is .209

Explanation:

I am unable to show the work for this as I did it online but I can assure you it is correct

Given that,

Mass of satellite = 500 kg

Gravitational force = 3000 N

We need to calculate the radius of the circular orbit

Using formula of gravitational force

[tex]F_{g}=\dfrac{GMm}{(R+h)^2}[/tex]

Where, G = gravitational constant

R = radius of earth

h = radius of the circular orbit

M = mass of earth

m = mass of satellite

Put the value into the formula

[tex]3000=\dfrac{6.67\times10^{-11}\times500\times6\times10^{24}}{(6.4\times10^{6})^2+h^2}[/tex]

[tex]h^2=\dfrac{6.67\times10^{-11}\times500\times6\times10^{24}-3000\times(6.4\times10^{6})^2}{3000}[/tex]

[tex]h=\sqrt{\dfrac{6.67\times10^{-11}\times500\times6\times10^{24}-3000\times(6.4\times10^{6})^2}{3000}}[/tex]

[tex]h=5073460.35\ m[/tex]

[tex]h=5.1\times10^{6}\ m[/tex]

(II). We need to calculate the speed of the satellite

Using formula of velocity

[tex]v=\sqrt{\dfrac{GM}{r}}[/tex]

Put the value into the formula

[tex]v=\sqrt{\dfrac{6.67\times10^{-11}\times6\times10^{24}}{5.1\times10^{6}}}[/tex]

[tex]v=8858.36\ m/s[/tex]

[tex]v=8.8\times10^{3}\ m/s[/tex]

[tex]v=8.8\ km/s[/tex]

(III). We need to calculate the period of the orbit

Using formula of  time period

[tex]T=2\pi\sqrt{\dfrac{r^3}{GM}}[/tex]

Put the value into the formula

[tex]T=2\pi\sqrt{\dfrac{(5.1\times10^{6})^3}{6.67\times10^{-11}\times6\times10^{24}}}[/tex]

[tex]T=3617.40\ sec[/tex]

[tex]T=1.00\ hr[/tex]

Hence, (I). The radius of the circular orbit is [tex]5.1\times10^{6}\ m[/tex]

(II). The speed of the satellite is 8.8 km/s.

(III). The period of the orbit is 1.00 hr.

Answer: 390, right

explanation: The net force is just the sum of all of these forces acting on an object. ... This equation is the sum of n forces acting on an object. The magnitude of the net force acting on an object is equal to the mass of the object multiplied by the acceleration of the object, as shown in this formula.

the net force acting on the buggy is 390 and The net force is pointing to the is right

The following information should be considered:

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Answer:

the ability of data to be duplicated well described reproducibility

Explanation:

Reproducibitity of a data is the ability of a data to be produced in multiple times using the same procedure. It is used to test how precise a data is and it's usually known as standard deviation

Reproducibility is the closeness of the understanding between the consequences of measurements of the equivalent measurand did with a similar procedure depicted in the relating logical proof (for example a distribution in a companion surveyed diary).

Answer:

the ability of data to be duplicated well described reproducibility

Answer:

38.7°

Explanation:

Draw a free body diagram of the car.  There are three forces:

Weight force mg pulling down,

Normal force N pushing up perpendicular to the incline,

and friction force Nμ pushing parallel up the incline.

Sum of forces in the perpendicular direction:

∑F = ma

N − mg cos θ = 0

N = mg cos θ

Sum of forces in the parallel direction:

∑F = ma

Nμ − mg sin θ = 0

Nμ = mg sin θ

μ = (mg sin θ) / N

μ = (mg sin θ) / (mg cos θ)

μ = tan θ

Given μ = 0.8:

θ = tan⁻¹(0.8)

θ = 38.7°

Answer:

amongst the properties that makes aluminium a metal is that it is malleable and ductile...and it has high melting and boiling points

I hope that helps

Explanation:

properties of metals include

1. high melting and boiling points

2 high densities

3 malleability and ductility

Answer: 3.75 m/s

Explanation:

Average speed is distance covered per time taken.

If the time interval is from t = 2 to t = 10s

Then, the time taken will be

t = 10 - 2 = 8s

Given that the distance covered are 10 + 8 - 2 + 10

Since distance is a scalar quantity, we will only consider the magnitude and not the direction.

Total distance = 10 + 8 + 2 + 10 = 30m

Average speed = total distance/time

Substitute total distance and time into the formula

Average speed = 30/8

Average speed = 3.75 m/s