Which material is a composite? A. gold B.silicon C.polycarbonate D.aluminum

Answer:

42.1m/s

Explanation:

Given parameters:

Height of cliff = 239m

 Free fall acceleration  = -3.7m/s²

Unknown:

Final velocity of the camera = ?

Solution:

When the body is falling under free fall, the acceleration  =  3.7m/s² ;

The appropriate motion equation is:

             V² = U² + 2gH

V = final velocity

U = initial velocity

g = free fall acceleration

H = height of the fall

  Insert the parameters and solve;

 U  = 0

 V² = 0² +  2 x 3.7 x 239

 V² = 1768.6

V  = 42.1m/s

Answer:

Explanation:

The acceleration of an object given it's mass and the force acting on it can be found by using the formula

[tex]a = \frac{f}{m} \\ [/tex]

f is the force

m is the mass

From the question we have

[tex]a = \frac{20}{30} = \frac{2}{3} \\ = 0.6666666...[/tex]

We have the final answer as

Hope this helps you

Answer:

It allows electrons to flow from one part of the circuit to another

when it is closed.

Explanation:

hope this helps <3 !!

Answer: D

Explanation:

Answer:

2.78J

3.64cm

Explanation:

Natural length is 36 and stretches to 45. 5 J of work is needed

5 = 1/2k(0.45-0.36)²

5 = 1/2k(0.09)²

5 = 0.0081k/2

10 = 0.0081k

K = 1234.568

X1 = 0.38-0.36 = 0.02

X2 = 0.43-0.36 = 0.07

Work done

W = 1/2k(x2²-x1²)

W = 1/2(1234.568)(0.007²-0.02²)

W = 1234.568(0.0049-0.0004)/2

W = 2.78j

F = 45N

F = kx

X = f/k

= 45/1234.568

= 0.0364

= 3.64cm

The answer to A is 2.78j

The answer to b is 3.64cm

Answer:

[tex]\mu=0.5[/tex]

Explanation:

Given that,

Applied force, F = 200 N

Weight of the object, or the normal force, N = 400 N

We need to find the coefficient of static friction between the object and the surface.

The force of friction has the same magnitude as that of applied force. It can be given by :

[tex]F=\mu mg[/tex]

mg is weight of the object

[tex]\mu=\dfrac{F}{mg}\\\\\mu=\dfrac{200}{400}\\\\\mu=0.5[/tex]

So, the coefficient of static friction between the object and the surface is 0.5.

Answer:

An internal-combustion engine goes through four strokes: intake, compression, combustion (power), and exhaust. As the piston moves during each stroke, it turns the crankshaft.

Answer:

The engine will not work causing no movement in the wheels .

Explanation:

Remember the four stroke combustion cycle powers the wheels and if one of these parts do not work, then the car will not move .

Answer:

F =  3.32 x 10⁻⁶ N

Explanation:

The force of attraction between two masses is given by Newton's Law of Gravitation, as follows:

F = Gm₁m₂/r²

where,

F = Force between Romeo and Juliet = ?

G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²

m₁ = mass of Romeo = 68 kg

m₂ = mass of space station = 4.58 x 10⁵ kg

r = distance = 25 m

Therefore,

F = (6.67 x 10⁻¹¹ N.m²/kg²)(68 kg)(4.58 x 10⁵ kg)/(25 m)²

F =  3.32 x 10⁻⁶ N

Hans Oersteds works with electricity and magnetism is that he developed electromagnetism when he observed compass needle that was deflected when electric current flow through it.

Electromagnetism is a type of electromagnetic force that occur between electric field and magnetic field and the interaction that exhaust between them and charged particles.

Therefore, Hans Oersteds works with electricity and magnetism is that he developed electromagnetism.

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Answer:

The temp. of the metal will decrease

Explanation:

Hope this helps!

Answer:

(a) The time taken for the plane to reach 50 km/hr is 811.97 s

(b) (i) the acceleration of the plane is 0.012 m/s²

    (ii) The time taken for the plane to reach 50 km/hr is 1172.85 s

Explanation:

Given;

mass of the freight train, m = 3.8 x 10⁷ kg

force applied to pull the train, F = 6.5 x 10⁵ N

a. How long does it take the train to go from rest to 50 km/hr?

Given;

initial velocity, u = 0

final velocity, v = 50 km/hr = 13.889 m/s

Apply Newton's second law of motion to determine the time traveled by the train at the given speed;

[tex]F = ma = \frac{m(v-u)}{t}\\\\t = \frac{m(v-u)}{F}\\\\t = \frac{3.8*10^7(13.889-0)}{6.5*10^5}\\\\t = 811.97 \ s[/tex]

(b)

(i) the acceleration of the plane

Given;

air resistance, = 2.0 x 10⁵ N

Apply Newton's second law of motion;

∑F = ma

6.5 x 10⁵ N - 2.0 x 10⁵ N = ma

4.5 x 10⁵ N = ma

[tex]a = \frac{4.5 * 10^5 }{m}\\\\a = \frac{4.5 * 10^5 }{3.8*10^7}\\\\a = 0.012 \ m/s^2[/tex]

(ii) time taken for the plane to reach 50 km/hr is given by;

[tex]F = \frac{m(v-u)}{t}\\\\t = \frac{m(v-u)}{F}\\\\t = \frac{3.8*10^7(13.889-0)}{4.5*10^5}\\\\t = 1172.85 \ s[/tex]

Answer:

[tex]\huge\boxed{\sf Hen's \ Egg}[/tex]

Explanation:

Seen with an unaided eye means that is visible to the naked eye.

So,

Hen's Egg can be seen with an unaided eye.

However, Red Blood Cells (RBCs) and Sperm cells need a microscope for them to be seen!

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

The unit that should be used to measure energy when calculating specific heat capacity is Energy is in Joules ( J ).

The specific heat capacity should be determined in joules per kilogram degree-celsius ( J k g − 1 ∘ C − 1 ).

It is to be supplied for the substance with respect to mass and it increased the temperature.

Hence, The unit that should be used to measure energy when calculating specific heat capacity is Energy is in Joules ( J ).

Learn more about unit here: https://brainly.com/question/16660726

The unit used to measure energy when calculating specific heat capacity is the joule (J).

The joule (J), a unit used to quantify energy, is used to calculate specific heat capacity. In the International System of Units (SI), the joule serves as the default unit of energy.

It is described as the quantity of energy that is delivered when one newton of force is exerted across a one-meter distance.

Thus, the quantity of heat energy needed to increase the temperature of a particular substance by a specific amount is measured as specific heat capacity. J/kg°C, or joules per kilogramme per degree Celsius, is the unit of measurement.

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Answer:

Explanation:

To find the mass of the box we use the formula

[tex]m = \frac{w}{d} \\ [/tex]

w is the workdone

d is the distance

From the question we have

[tex]m = \frac{7000}{1.2} \\ = 5833.3333...[/tex]

We have the final answer as

Hope this helps you

Explanation:

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Answer:

350 N

Explanation:

Newton's second law:

∑F = ma

∑F = (175 kg) (2 m/s²)

∑F = 350 N

Answer:

Explanation:

Potassium is the correct answer

Answer:

[tex]\huge\boxed{Potassium}[/tex]

Explanation:

Group I elements are called alkali metals and are soft but highly reactive (because they have only 1 electron in their outermost shell). Potassium is of Group I (Alkali metal) and is thus soft and highly reactive.

Magnesium and Calcium both are of Group II (Alkaline Earth Metals).

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

Explanation:

See attached file.

you need to attach a picture so I can answer it

Answer:

not enough avidence is the correct answer

Answer:

I had to search the Figure on Google to solve this question.

a) The magnitude of the force F₃ is:

[tex] F_{3} = 87.47 N [/tex]

And the direction of F₃:

[tex] \alpha = 79.04 ^{\circ} [/tex]  (with respect to the y-direction, in the third quadrant)

b) P = 4.22 N  

Explanation:

I had to search the Figure on Google to solve this question.

a) We can find the force of the third person as follows:

[tex] \Sigma F_{x} = F_{1x} + F_{2x} + F_{3x} = 0 [/tex]

[tex] \Sigma F_{y} = F_{1y} - F_{2y} + F_{3y} = 0 [/tex]

So, in x-direction we have:

[tex] \Sigma F_{x} = 45 N*cos(70) + 75 N*cos(20) + F_{3x} = 0 [/tex]

[tex] F_{3x} = -85.87 N [/tex]

In y-direction we have:

[tex] \Sigma F_{y} = 45 N*sin(70) - 75 N*sin(20) + F_{3y} = 0 [/tex]

[tex] F_{3y} = -16.63 N [/tex]

The magnitude of the force F₃ is:

[tex] F_{3} = \sqrt{F_{3x}^{2} + F_{3y}^{2}} = \sqrt{(-85.87 N)^{2} + (-16.63 N)^{2}} = 87.47 N [/tex]

To find the direction of F₃ we need to calculate its angle with respect to the y-direction (in the third quadrant):

[tex] tan(\alpha) = \frac{|F_{3x}|}{|F_{3y}|} = \frac{85.87 N}{16.63 N} [/tex]

[tex] \alpha = 79.04 ^{\circ} [/tex]

b) If the third person exerts the force found in part (a) the car will stop, so the only way for the cart to accelerate at 200 m/s² is that the third person does not exert the force found in a.      

To find the weight of the cart​ when it accelerates at 200 m/s², we need to consider: F₃ = 0.  

First, we need to find the cart's mass. Since the car is moving in the x-direction we have:

[tex] \Sigma F_{x} = F_{1x} + F_{2x} = ma [/tex]

[tex] 45 N*cos(70) + 75 N*cos(20) = m*200 m/s^{2} [/tex]

[tex] m = \frac{45 N*cos(70) + 75 N*cos(20)}{200 m/s^{2}} = 0.43 kg [/tex]

Now, the weight of the cart​ is:

[tex] P = mg = 0.43 kg*9.81 m/s^{2} = 4.22 N [/tex]

I hope it helps you!                                                                                    

Answer:

B)8

Explanation:

In the first energy level you can have, at most, 2. Every energy level after that wants to have 8 electrons. Valence electrons I believe.

Hope this helps, have a nice day! (^-^)

Answer:

equal and unlike charges

Explanation:

Answer:

[tex]\huge\boxed{\sf Equal \ and \ unlike \ charges}[/tex]

Explanation:

When two bodies are rubs against each other, Charges of equal magnitude are induced in them. However, they are of equal magnitude but the charges are opposite and unlike.

For Example:

If we rub an iron rod with a cotton cloth, a positive charge will be induced in the iron rod and a negative charge will be induced in the cotton cloth. Note that the charges will be of equal magnitude.

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Let me know if you have any q's regarding this!

Answer:

Power is a scalar quantity and has a unit,a magnitude(a numerical value) but no direction.

Explanation:

Answer:

yeah

Explanation:

yeah yeah yeah yeah

Answer:

The radius of the bubble when it reaches the surface at 30 ºC is 1.015 centimeters.

Explanation:

Let suppose that air bubble behaves as ideal gas, whose equation of state is:

[tex]P\cdot V = n\cdot R_{u}\cdot T[/tex] (Eq. 1)

Where:

[tex]P[/tex] - Pressure of the bubble, measured in kilopascals.

[tex]V[/tex] - Volume of the bubble, measured in cubic meters.

[tex]n[/tex] - Molar amount of the bubble, measured in kilomoles.

[tex]T[/tex] - Temperature, measured in Kelvin.

[tex]R_{u}[/tex] - Ideal gas constant, measured in kilopascal-cubic meter per kilomole-Kelvin.

Then, we eliminate the molar amount and the ideal gas constant by constructing the following relationship:

[tex]\frac{P_{A}\cdot V_{A}}{T_{A}} = \frac{P_{B}\cdot V_{B}}{T_{B}}[/tex] (Eq. 2)

Where:

[tex]P_{A}[/tex], [tex]P_{B}[/tex] - Pressure of the bubble at bottom and surface, measured in kilopascals.

[tex]V_{A}[/tex], [tex]V_{B}[/tex] - Volume of the bubble at bottom and surface, measured in cubic meters.

[tex]T_{A}[/tex], [tex]T_{B}[/tex] - Temperature of the bubble at bottom and surface, measured in Kelvin.

The pressure experimented by the bubble at bottom and surface are, respectively:

[tex]P_{A} = 101.325\,kPa+\left(1027\,\frac{kg}{m^{3}} \right)\cdot \left(9.807\,\frac{kg}{m^{3}} \right)\cdot (25\,m)\cdot \left(\frac{1}{1000}\,\frac{kPa}{Pa} \right)[/tex]

[tex]P_{A} = 353.120\,kPa[/tex]

[tex]P_{B} = 101.325\,kPa[/tex]

If we know that [tex]P_{A} = 353.120\,kPa[/tex], [tex]P_{B} = 101.325\,kPa[/tex], [tex]V_{A} = 1.20\times 10^{-6}\,m^{3}[/tex], [tex]T_{A} = 290.15\,K[/tex] and [tex]T_{B} = 303.15\,K[/tex], then the volume of the bubble at surface is:

[tex]\frac{(353.120\,kPa)\cdot (1.20\times 10^{-6}\,m^{3})}{290.15\,K} = \frac{(101.325\,kPa)\cdot V_{B}}{303.15\,K}[/tex]

[tex]1.460\times 10^{-6} = 0.334\cdot V_{B}[/tex]

[tex]V_{B} = 4.372\times 10^{-6}\,m^{3}[/tex]

[tex]V_{B} = 4.372\,cm^{3}[/tex]

And the volume of the air bubble is determined by this formula:

[tex]V_{B} = \frac{4\pi\cdot R^{3}}{3}[/tex] (Eq. 3)

Where [tex]R[/tex] is the radius of the air bubble, measured in centimeters.

If we know that [tex]V_{B} = 4.372\,cm^{3}[/tex], then the radius of the air bubble is:

[tex]4.372 = \frac{4\pi\cdot R^{3}}{3}[/tex]

[tex]R^{3} = 1.044[/tex]

[tex]R \approx 1.015\,cm[/tex]

The radius of the bubble when it reaches the surface at 30 ºC is 1.015 centimeters.

Explanation:

The question is incomplete. To get the voltage V across the resistors, we need to total current flowing in the circuit.

Let the current I = 6 A

According to ohms law, V = IRt

V is the total voltage

I is the total current

Rr is the total effective resistance

Since the 2 4ohms resistors are connected in parallel;

1/Rt = 1/4 + 1/4

1/Rt = 2/4

Cross multiply

2Rt = 4

Rt = 4/2

Rt = 2 ohms

Get the voltage V.

V = IRt

V = 6(2)

V = 12V

Hence the required voltage will be 12V

Note that the value of the current used was assumed. The same calculation can be employed for any value of the current

Answer:

Explanation:

According to law of conservation of momentum

m1u1+ m2u2 = (m1+m2)v

m1 and m2 are the masses of the object

u1 and u2 are their initial velocities

v is their common velocity

Given

m1 = 3kg

m2 = M

u1 = 8m/s

u2 = 0m/s (object at rest)

v = 6.0m/s

Substitute and get M

3(8) + M(0) = (3+M)6

24 = 18+6M

24-18 = 6M

6 = 6M

M = 1kg

Hence the mass M is 1kg

Answer:

1. Initial conditions

2. The speed of a character at the moment of contact

3. The hardness of the sidewalk where the mug landed

4. The location where potential energy is zero

5. Aerodynamic properties

Explanation:

100%

The values that may change over time in a model are called initial conditions.

Scientists use models to represent actual conditions. A model is always a representation of real life situations and are very useful for explanatory and predictive purposes.

When scientists make models of dynamic physical events, they will normally choose to have values that may change as time progresses. These values are called initial conditions.

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Answer:

brain

Explanation:

brain and blood