what two properties change when light is refracted

Answer:

is that rm in you profile pic

Answer:

The speed of the train when the tail buffers pass the lamp post is 9 m/s

Explanation:

The given parameters are;

The length of the train = 90 m

The initial velocity of the train, u = 0

The average acceleration of the train, a = 0.45 m/s²

When the tail buffer pass the lamp post, P, we have;

The distance travelled, s = The length of the train = 90 m

The kinematic equation of motion is given as follows;

v² = u² + 2·a·s

Where;

v = The speed of the train when the tail buffers pass the lamp post

∴ v² = 0² + 2 × 0.45 m/s² × 90 m = 81 m²/s²

Therefore;

v = √(81 m²/s²) = 9 m/s

The speed of the train when the tail buffers pass the lamp post, v = 9 m/s.

Answer:

To indicate short quotations (four typed lines or fewer of prose or three lines of verse) in your text, enclose the quotation within double quotation marks.

Answer:

it means that the force of attraction between two object in gravitation is 6.67×10-11N

It means that the force of attraction between two object in gravitation is 6.67×10-11N.

The formula is g = GM/r2, Where M is the mass of the Earth, r is the radius of the Earth (or distance between the center of the Earth and you, standing on its surface), and G is the gravitational constant. G (without the subscripts) is the gravitational constant, and c is the speed of light.

The gravitational force between two objects is proportional to their masses and inversely proportional to the square of the distance between their centers. joining the two centers of masses.

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applied force is a contact force

Explanation:

tilting it will raise the height of its center of gravity.

Answer:

Organic farming would have higher costs, and would be more complex than conventional farming. However, the Suarez family could charge a higher price for organic produce. This type of farming also would be better for the land.

Explanation:

Answer expert verified for the same question. (question/4178423)

Answer:

DU = -80 Joules

Explanation:

Given the following data;

Work done = 100 J

Quantity of heat = 20 J

To find change in internal energy of the gas;

Mathematically, the change in internal energy of a system is given by the formula;

DU = Q - W

Where;

DU is the change in internal energy.

Q is the quantity of energy.

W is the work done.

Substituting the values into the formula, we have;

DU = 20 - 100

DU = -80 Joules

Therefore, the final energy of the gas is lower than its initial energy.

Answer:

d I guess not sure

b if down I guess

Explanation:

if worng then plz dont say anything as I am not sure about the ans

The final temperature of the mixture is 43.62 °C, If 200 ml of tea at 90 °C is poured into a 400 g glass cup initially at 25 °C.

To solve the question above, we apply the law of calorimetry

The law of calorimetry: which states that if there is no lost of heat the surrounding, heat lost is equal to heat gained, or it can be stated as heat absorbed by a cold body is equal to heat released by a hot body, provided there is no lost of heat to the surrounding.

The law above is expressed mathematically as

[tex]Cm(T-t) = C'm'(t-T')[/tex]............. Equation 1

Using equation 1 to solve the question,

[tex]0.4(840)(90-t) = 0.2(4186)(t-25)[/tex]

[tex]336(90-t) = 837.2(t-25)[/tex]

[tex]30240-336t = 837.2t-20930[/tex]

collect like terms

[tex]837.2t + 336t = 30240+20930[/tex]

[tex]1173.2t = 51170[/tex]

[tex]t = 51170/1173.2[/tex]

[tex]t = 43.62[/tex] °C

Hence, the final temperature of the mixture is 43.62 °C

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Answer:

The final temperature of the system is 41.657 °C.

Explanation:

Let consider the tea-cup system as an isolated system, that is, a system with no energy and mass interactions with the surroundings. From the perspective of the First Law of Thermodynamics, the tea releases heat, which is received by the glass cup until thermal equilibrium is reached. The following formula represents the model under assumption that process was at steady state:

[tex]\rho_{w}\cdot V\cdot c_{w}\cdot (T_{w,o}-T) + m_{g}\cdot c_{g}\cdot (T_{g,o}-T) = 0[/tex] (1)

Where:

[tex]\rho_{w}[/tex] - Density of water, in grams per mililiter.

[tex]V[/tex] - Volume of tea, in mililiters.

[tex]c_{w}[/tex] - Specific heat of water, in joules per gram-degree Celsius.

[tex]m_{g}[/tex] - Mass of the glass cup, in kilograms.

[tex]c_{g}[/tex] - Specific heat of the glass cup, in joules per gram-degree Celsius.

[tex]T_{w,o}[/tex] - Initial temperature of tea, in degrees Celsius.

[tex]T_{g,o}[/tex] - Initial temperature of the glass cup, in degrees Celsius.

[tex]T[/tex] - Final temperature of the tea-cup system, in degrees Celsius.

If we know that [tex]\rho_{w} = 1\,\frac{g}{mL}[/tex], [tex]V = 200\,mL[/tex], [tex]c_{w} = 4.186\,\frac{J}{g\cdot ^{\circ}C}[/tex], [tex]m_{g} = 400\,g[/tex], [tex]c_{g} = 0.840\,\frac{J}{g\cdot ^{\circ}C}[/tex], [tex]T_{w,o} = 90\,^{\circ}C[/tex] and [tex]T_{g,o} = 25\,^{\circ}C[/tex], then the final temperature of the tea-cup system is:

[tex]\rho_{w}\cdot V\cdot c_{w}\cdot (T_{w,o}-T) + m_{g}\cdot c_{g}\cdot (T_{g,o}-T) = 0[/tex]

[tex]\rho_{w}\cdot V\cdot c_{w}\cdot T_{w,o} +m_{g}\cdot c_{g}\cdot T_{g,o} - (\rho_{w}\cdot V\cdot c_{w}+m_{g}\cdot c_{g})\cdot T = 0[/tex]

[tex]T = \frac{\rho_{w}\cdot c_{w}\cdot T_{w,o}+m_{g}\cdot c_{g}\cdot T_{g,o}}{\rho_{w}\cdot V\cdot c_{w}+m_{g}\cdot c_{g}}[/tex]

[tex]T = \frac{\left(1\,\frac{g}{mL} \right)\cdot \left(4.186\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (200\,mL)\cdot (90\,^{\circ}C)+(400\,g)\cdot \left(0.840\,\frac{J}{g\cdot ^{\circ}C} \right)\cdot (25\,^{\circ}C)}{\left(1\,\frac{g}{mL} \right)\cdot \left(4.186\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (200\,mL) +(400\,g)\cdot \left(0.840\,\frac{J}{g\cdot ^{\circ}C} \right)}[/tex]

[tex]T = 41.657\,^{\circ}C[/tex]

The final temperature of the system is 41.657 °C.

Answer:

A

in performing the experiment the hypothesis is proved wrong or correct prediction , meaning of prediction is guessing,

hypothesis the second stage of scientific method , scientist predict or guess the answer to the problem ,

Experiment the third stage of scientific method

scientist examine the ways

"Perform the experiment" is the step of the scientific method where a scientist determines whether the hypothesis was supported.

In the scientific method, experiments (often with controls and variables) are devised to test hypotheses. In the scientific method, analysis of the results of an experiment will lead to the hypothesis being accepted or rejected.

The basic idea of a hypothesis is that there is no predetermined outcome. For a solution to be termed a scientific hypothesis, it has to be an idea that can be supported or refuted through carefully crafted experimentation or observation.

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Answer:

1.12 × 10⁴ m/s

Explanation:

The escape velocity of the object v = √(2GM/R) where G = gravitational constant = 6.67 × 10⁻¹¹ Nm²/kg², M = mass of the Earth = 6 × 10²⁴ kg and R = radius of the Earth = 6.4 × 10⁶ m

Since v = √(2GM/R)

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

v = √(2GM/R)

v = √(2 × 6.67 × 10⁻¹¹ Nm²/kg² × 6 × 10²⁴ kg/6.4 × 10⁶ m)

v = √(13.34 × 10⁻¹¹ Nm²/kg² × 6 × 10²⁴ kg/6.4 × 10⁶ m)

v = √(80.04 × 10⁻¹¹ × 10²⁴Nm²/kg/6.4 × 10⁶ m)

v = √(80.04 × 10¹³Nm²/kg ÷ 6.4 × 10⁶ m)

v = √(80.04 ÷ 6.4 × 10¹³ ÷ 10⁶Nm/kg)

v = √(12.50625 × 10⁷ Nm/kg)

v = √(125.0625 × 10⁶ Nm/kg)

v = 11.18 × 10³ m/s

v = 1.118 × 10 × 10³ m/s

v = 1.118 × 10⁴ m/s

v ≅ 1.12 × 10⁴ m/s

Answer:

The beam balance is a device used for the determination of the mass of a body under gravitation. Beam balance is used for high precision measurements like masses up to 250g, it consists of a pair of scale pans one at each end of a rigid beam.

we use a scale to measure the weight of our bodies

Answer:

Slowly and smoothly lol

Answer:

S.I. on Rs. 1600 = T.D. on Rs. 1680. Rs. 1600 is the P.W. of Rs. 1680, i.e., Rs. 80 is on Rs. 1600 at 15%. Time =100 x 80year=1year = 4 months.1600 x 153

Explanation:

Is this you are?

Answer:

just add co-ratios and then find the average.

Explanation:

Answer:

Explanation:

Here,

Final mass(m)=150g

Final Temperature(t)=60°C

Temperature of hot water(t1)=90C

Temperature of cold water(t2)=14C

Let the grams of water to be used per face be m1 grams and (150-m1) grams for hot and cold water respectively.

We know that,

Heat lost by hot body=Heat gained by cold body

or, m1 s1 Δt1=m2 s2 Δt2

or, m1 (t1-t)=(150-m1) (t-t2)  [∵s1=s2, SHC of water is taken to be same]

or, m1 (90-60)=(150-m1) (60-14)

or, 30m1=6900-46m1

or, 76m1=6900

∴m1=90.79g

(150-m1)=59.21g

Hence, 90.79g and 59.21 g hot and cold water must be used respectively.

Answer:

drop in water

Explanation:

follow me m mm m

If the sound comes from the right side, the waves reach the right ear before the left ear. if the sound comes from the left side, the waves reach the left ear before the right ear. The difference between the phases of waves reaching both ears is detected by the ears and then interpreted by the brain

Answer:

The time taken is 1.76 s.

Explanation:

mass of student, m = 45 kg

height, h = 6 m

power, P = 1500 W

Power is defined as the rate of doing work.

Work done in moving height is

W = m g h

Let the time is t.

P = m g h / t

1500 = 45 x 9.8 x 6 / t

t = 1.76 s

Answer:

Explanation:

The main equation to solve this is F = ma, where F is the force applied to the brakes with respect to its acceleration. We have the mass that we need, but we do not have the acceleration. That's the first thing we have to find. However, our velocity needs to be stated in m/s and right now it's in km/h. Converting that:

[tex]90\frac{km}{hr}*\frac{1000m}{1km}*\frac{1hr}{3600s} =25\frac{m}{s}[/tex] Now we're ready to find the acceleration:

[tex]a=\frac{v_f-v_0}{t}[/tex] where the top line there translates to the final velocity minus the initial velocity.

[tex]a=\frac{0-25}{3.0}[/tex] so the acceleration is -8.3 m/s/s

We can use that now in the force equation above:

F = 1200(-8.3) and

F = -1.0 × 10⁴ N (that's 10,000 N to the correct number of sig dig's; the negative sign means that the force is being applied in the direction opposite to that which the van is currently moving)

Answer:

Explanation:

2. a

3. c

Answer:

6x+8=32

6x=32-8

6x=24

x=24:6

x= 4

vậy, x =4

Answer:

120 Nm-1

Explanation:

Según la ley de Hooke;

F = Ke

F = fuerza sobre el resorte

K = constante de fuerza

e = extensión

Por eso;

K = F / e

K = 24N / 20 × 10 ^ -2m

K = 120 Nm-1

Answer:

a)  [tex]h=25m[/tex]

b)  [tex]v=19.8m/sec[/tex]

Explanation:

From the question we are told that:

Height [tex]h=25m[/tex]

Bounce Height [tex]h'=20m[/tex]

Generally the Kinematic equation is mathematically given by

[tex]V=\sqrt{2gh}\\\\V=\sqrt{2*9.81*25}[/tex]

[tex]V=22.1m/sec[/tex]

Therefore Height

[tex]h=\frac{V^2}{2g}\\\\h=\frac{22.1^2}{2*9.81}[/tex]

[tex]h=25m[/tex]

b)

Generally the Kinematic equation is mathematically given by

[tex]v^2=2ah[/tex]

[tex]v^2=2*9.8*20[/tex]

[tex]v=\sqrt{2*9.8*20}[/tex]

[tex]v=19.8m/sec[/tex]

Answer:

resistances is inversely proportional to the area of cross section of the conductor

Explanation:

The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area.

hope this helps you

have a nice day:)

Answer:

The northern lights come from the interaction of electrically charged particles given off by the Sun surface during solar storms and the Earth's magnetic field which is pointed in the northern to southern poles of the Earth. Therefore, the charged particles that travel through millions of miles from the Sun to the Earth accelerate towards the magnetic poles and appear as the northern (and southern) lights

Boreal is an adjective word for the north or northern regions. In the southern latitudes, in the southern hemisphere, the phenomenon is called aurora australis (australis is the adjective for 'of the south')

Explanation:

Answer: There are multiple options:

By varying the supply voltage.

By varying the flux, and by varying the current through the field winding.

By varying the armature voltage, and by varying the armature resistance.

Helpful Link:

https://www.elprocus.com/what-are-the-best-ways-to-control-the-speed-of-dc-motor/

Explanation:

C. Both energy and matter