A uniform plank of mass 10kg and length 10m rests on two supports, A and B as shown. A boy of weight 500N stands at a distance of 2m from A. Find the reaction forces U¹ and U² at the supports A and B respectively​

Answer:

The average impact force is 12000 newtons.

Explanation:

By Impact Theorem we know that impact done by the sledge hammer on the chisel is equal to the change in the linear momentum of the former. The mathematical model that represents the situation is now described:

[tex]\bar F \cdot \Delta t = m \cdot (v_{2}-v_{1})[/tex] (1)

Where:

[tex]\bar F[/tex] - Average impact force, in newtons.

[tex]\Delta t[/tex] - Duration of the impact, in seconds.

[tex]m[/tex] - Mass of the sledge hammer, in kilograms.

[tex]v_{1}[/tex], [tex]v_{2}[/tex] - Initial and final velocity, in meters per second.

If we know that [tex]\Delta t = 0.0020\,s[/tex], [tex]m = 4\,kg[/tex], [tex]v_{1} = -6\,\frac{m}{s}[/tex] and [tex]v_{2} = 0\,\frac{m}{s}[/tex], then we estimate the average impact force is:

[tex]\bar F = \frac{m\cdot (v_{2}-v_{1})}{\Delta t}[/tex]

[tex]\bar F = 12000\,N[/tex]

The average impact force is 12000 newtons.

Answer:

An example of changes in people based on their age, are mood changes,playfulness and as of objects you can say old or broken, animals can use the same reference as humans, the more mature you are can suggest your older, such as the more worn down your are based on a object

Answer:

7.45 Ω

Explanation:

From the question given above, the following data were obtained:

Resistor 1 (R₁) = 2.50 Ω

Resistor 2 (R₂) = 4.95 Ω

Voltage (V) = 12 V

Equivalent Resistance (Rₑq) =?

Since the resistors are in series arrangement, the equivalent resistance can be obtained as follow:

Rₑq = R₁ + R₂

Rₑq = 2.5 + 4.95

Rₑq = 7.45 Ω

Therefore, the equivalent resistance is 7.45 Ω

Answer:

4.83 °C

Explanation:

001 = λ*ΔT

ΔT = 10^-3*10^6/207 = 4.83°C

Answer:

4.83

Explanation:

Answer:

'Wave' is a common term for a number of different ways in which energy is transferred: In electromagnetic waves, energy is transferred through vibrations of electric and magnetic fields. In sound waves, energy is transferred through vibration of air particles or particles of a solid through which the sound travels.

Answer:

Ok.............

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Answer:

electrons move around nucleus in specific regions

We have that the correct statement that summarizes atoms over time will be

The discovery of new evidence resulted in changes to the atomic theory.

Option B

Generally

The Image shows that in the early 1800 the knowledge of atom was limited and it increased over time and by 1920 it had gone through a 4 stages of modifications to the atomic model

Therefore the correct statement that summarizes atoms over time will be

The discovery of new evidence resulted in changes to the atomic theory

For more information on this visit

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Answer:

A) It requires extremely high pressure.

Explanation:

The reasons why we haven't been able to harness power from fusion is that its energy requirements are unbelievably, terribly high.

The correct statement is: "nuclear fusion requires extremely high pressure."

To find the correct statement among all the options, we need to know about nuclear fusion.

What is nuclear fusion?

How much pressure is required for nuclear fusion?

How much energy is released during nuclear fusion?

What is the comparison of energy that released in nuclear fusion and fission?

How does we get energy in the nuclear fusion reaction?

Thus, we conclude that option (A) is correct.

Learn more about nuclear fusion here:

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#SPJ2

Answer:

The second (abbreviation, s or sec) is the Standard International ( SI ) unit of time. One second is the time that elapses during 9,192,631,770 (9.192631770 x 10 9 ) cycles of the radiation produced by the transition between two levels of the cesium 133 atom. ... One second is equal to 1/86,400 of a mean solar day.

Explanation:

[tex]\Large {{ \sf {Question :}}} [/tex]

[tex]\Large {{ \sf {Given :}}} [/tex]

[tex]\Large {{ \sf {Formulae :}}} [/tex]

[tex]a \: = \frac{v - u}{t} \\ or \: \: a = \frac{(15 - 5)}{10} m \: s^{ - 2} \\ or \: \: a \: = \frac{10}{10}m \: s^{ - 2} \\ or \: \: a = 1m \: s^{ - 2} [/tex]

[tex]\Large {{ \sf {Answer :}}} [/tex]

Answer:

I think that the answer might be d

Answer:

D

Explanation:

If a car is moving very fast in a straight road or a highway in such a way that it has reached its limits as soon as it is going that fast it can break it limit

Answer:

119 cm

Explanation:

Given heights :  200cm , 188 cm , 175 cm, 160 cm

since the eyes are at 95% level

95% of 200 cm = 190 cm

95% of 160 cm = 152 cm

hence the allowable height of mirror = 200 - ( 5 + 76 ) = 119 cm

and The mirror should be hung 75cm from the floor

Answer:

To stop a car must lose its momentum and its kinetic energy. ... If the forces on two cars are equal then the greater the kinetic energy the greater the distance before stopping. But there will be a relationship to the momentum because momentum and mass are both related to the kinetic energy.

Answer:

Explanation:

Heat gained by ice in warming up to 0⁰C = .035 x 2090 x (83-0)= 6071.45 J

heat used up by ice to melt at 0⁰C = .035 x 3.33 x 10⁵ J = 11655 J

Heat used up in warming up water to t⁰C = .035 x 4186 x t = 146.51 t

heat released by warm water to cool from 22⁰C to t = .565 x 4186 x ( 22 - t )

=52032 -2365.1 t

heat released by copper calorimeter  to cool from 22⁰C to t =  .087 x 387 x ( 22 - t ) = 740.72 - 33.7 t

total heat released = 52032 -2365.1 t  + 740.72 - 33.7 t

= 52772.72 - 2398.8 t

Heat lost = heat gained

52772.72 J- 2398.8 t  = 6071.45 J + 11655 J + 146.51 t

2545.31 t = 35046.27

t = 13.8°C.

Answer:

I have no idea.

Explanation:

I just wanted to tell you I absolutely read this wrong.

Answer:

its D

Explanation:

i just got it correct on a. p. e. x. :)

Answer:

Fossils are the preserved remains or traces of animals, plants, and other organisms from the past. Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today.

Explanation:

Answer:

Thus 1 Ampere is the current is defined as flow of 1 coulomb charge through a conductor in 1 second.

Explanation:

Hope it helps

Explanation:

speed : • how fast an object changes position

• miles per hour.

• distance/time.

velocity: • speed in a direction

• miles per hour North

• distance/ time in a direction

Answer:

45 N to the right possibly?

The resultant amplitude of the two waves is 1.0m

Resultant amplitude = 0.5m + 0.5m

Resultant amplutude = 1.0m

Hence the resultant amplitude of the two waves is 1.0m

Learn more about interference here: https://brainly.com/question/23044782

Answer:

Cornhole

Explanation:

Answer:  Density is measured in kg⋅m−2 . This means that it is derived from fundamental units which are the kilogram and metre. ... hence the kilogram and the metre are SI units and density is a derived unit from these units

Explanation:

they are calculated from the base units mass and length. Density is one derived unit; force, area, volume, specific volume and mass fraction are also derived units. Each derived unit is defined by a quantity equation.

Answer:

Density is obtained through mathematical manipulation.

Explanation:

A derived unit is obtained through mathematical calculation and the result is written with the S.I unit kg/m³

Answer:

The speed of the student just before she lands, v₂ is approximately 8.225 m/s

Explanation:

The given parameters are;

The mass of the physic student, m = 43.0 kg

The height at which the student is standing, h = 12.0 m

The radius of the wheel, r = 0.300 m

The moment of inertia of the wheel, I = 9.60 kg·m²

The initial potential energy of the female student, P.E.₁ = m·g·h₁

Where;

m = 43.0 kg

g = The acceleration due to gravity ≈ 9.81 m/s²

h = 12.0 h

∴ P.E.₁ = 43 kg × 9.81 m/s² × 12.0 m = 5061.96 J

The kinetic rotational energy of the wheel and kinetic energy of the student supporting herself from the rope she grabs and steps off the roof, K₁, is given as follows;

[tex]K_1 = \dfrac{1}{2} \cdot m \cdot v_{1}^2+\dfrac{1}{2} \cdot I \cdot \omega_{1}^2[/tex]

The initial kinetic energy, 1/2·m·v₁² and the initial kinetic rotational energy, 1/2·m·ω₁² are 0

∴ K₁ = 0 + 0 = 0

The final potential energy of the student when lands. P.E.₂ = m·g·h₂ = 0

Where;

h₂ = 0 m

The final kinetic energy, K₂, of the wheel and student is give as follows;

[tex]K_2 = \dfrac{1}{2} \cdot m \cdot v_{2}^2+\dfrac{1}{2} \cdot I \cdot \omega_{2}^2[/tex]

Where;

v₂ = The speed of the student just before she lands

ω₂ = The angular velocity of the wheel just before she lands

By the conservation of energy, we have;

P.E.₁ + K₁ = P.E.₂ + K₂

∴ m·g·h₁ + [tex]\dfrac{1}{2} \cdot m \cdot v_{1}^2+\dfrac{1}{2} \cdot I \cdot \omega_{1}^2[/tex] = m·g·h₂ + [tex]\dfrac{1}{2} \cdot m \cdot v_{2}^2+\dfrac{1}{2} \cdot I \cdot \omega_{2}^2[/tex]

Where;

ω₂ = v₂/r

∴ 5061.96 J + 0 = 0 + [tex]\dfrac{1}{2} \times 43.0 \, kg \times v_{2}^2+\dfrac{1}{2} \times 9.60 \, kg\cdot m^2 \cdot \left (\dfrac{v_2}{0.300 \, m} }\right ) ^2[/tex]

5,061.96 J = 21.5 kg × v₂² + 53.[tex]\overline 3[/tex] kg × v₂² = 21.5 kg × v₂² + 160/3 kg × v₂²

v₂² = 5,061.96 J/(21.5 kg + 160/3 kg) ≈ 67.643118 m²/s²

v₂ ≈ √(67.643118 m²/s²) ≈ 8.22454363 m/s

The speed of the student just before she lands, v₂ ≈ 8.225 m/s.

Answer:

The difference between the sidereal and synodic months occurs becuase as our moon moves around the earth, the earth also moves around our sun. Our moon must travel a little farther in its path to make up for the added distance and complete the phase cycle.

Explanation:

Hope this helps.

Answer:

Third option

Explanation:

To calculate meters per second you divide the distance by the time.

it's 8m/s