4. A motorist travels 406 km during a 9.0 hr period. What was the average speed in km/hr and m/s?

Answer:

Explanation:

The Law of Momentum Conservation, just like the Law of Thermodynamics about energy, says that momentum is neither created nor destroyed but is conserved, meaning it has to go somewhere. If the girl pushes the boy and they are both on friction free skates, then the girl will also react to the push. Momentum Conservation says

[tex](m_gv_g+m_bv_b)_b=(m_gv_g+m_bv_b)_a[/tex] In words this says that the mass times the velocity of the girl plus the mass times the velocity of the boy before the push has to equal the mass times velocity of the girl plus the mass times velocity of the boy after the push. Mathematically,

[tex](40.0*0+50.0*0)_b=(40.0v+50.0*-3)_a[/tex]

The left side of this is equal to 0. On the right, I made the velocity of the boy negative. We could have made it positive and it wouldn't have mattered. The sign will only be important to the result because if the sign of the girl's velocity is the same as the boy's, she is moving in the same direction as he is; if it's different, she is moving in the opposite direction.

0 = 40.0v - 150.0 and

-40.0v = -150.0 so

v = 3.75 This means that when she pushes the boy one way, mometum is conserved and she moves in the opposite direction and at a greater velocity (because her mass is less). Physics is a wonderful thing, isn't it!?

(a) 3.2 x 10²s

(b) 0.9 m/s (S 13 E)

(c) 2.9 x 10²m

The sketch illustrating the scenario has been attached to this response.

As shown;

The fish swims due east with a velocity [tex]V_{x}[/tex] = 0.2m/s

The river current has a velocity [tex]V_{y}[/tex] due South = 0.9m/s

The resultant of the velocity is V

The width of the river is x = 64m

(a) To calculate how long it took the fish to get across the river, we know that velocity is the rate of change in distance, therefore we can use the relation;

V = [tex]\frac{d}{t}[/tex]      -------------(i)

Where;

V = velocity of the fish = [tex]V_{x}[/tex] = 0.2m/s

d = distance from the start to the end = width of the river = x = 64m

t = time taken to move for that distance

Make t subject of the formula in equation (i);

t = [tex]\frac{d}{V}[/tex]

Substitute the values of d and V into the equation;

t = [tex]\frac{64m}{0.2m/s}[/tex]

t = 320 s

t = 3.20 x 10²s

Therefore, the time taken for the fish to get across the river is 3.20 x 10²s

(b) The resulting vector of the fish is V whose magnitude is the algebraic sum of vectors  [tex]V_{x}[/tex] and  [tex]V_{y}[/tex], and direction is given by θ. i.e

The magnitude of the resulting vector is;

|V| = [tex]\sqrt{(V_x)^2 + (V_y)^2}[/tex]

|V| = [tex]\sqrt{(0.2)^2 + (0.9)^2}[/tex]

|V| = [tex]\sqrt{(0.04) + (0.81)}[/tex]

|V| = [tex]\sqrt{(0.85)}[/tex]

|V| = 0.92m/s

|V| ≅ 0.9m/s

The direction of the resulting vector θ and is given by;

tan θ = [tex]\frac{V_y}{V_x}[/tex]

tan θ = [tex]\frac{0.9}{0.2}[/tex]

tan θ = 4.5

θ = tan⁻¹ ( 4.5)

θ = 77.47° South of East.

θ  ≈ 77.5° South of East.

Subtracting θ = 77.5° from 90° gives its value East of South

i.e

90 - 77.5 = 12.5° East of South

This can also be written as S12.5°E

Approximating to the nearest whole number gives S 13 E

Therefore, the resulting velocity of the fish is 0.9m/s in the direction S13°E

(c) When the fish arrives on the opposite bank, its distance from being at the point directly across from where it started is the product of the velocity of the river current and the time taken by the fish to get across the river. This point is equivalent to k as shown in the diagram.

Therefore;

distance = velocity of river current x time taken

distance = 0.9m/s x 3.20 x 10²s

distance = 2.88 x 10²m

distance ≅ 2.9 x 10²m

Notice that the velocity of the river current is used since that's the velocity of the fish on the y-axis.

Answer:

Explanation:

this is a simple application of Newton's 2nd Law: F = ma.

F = .019(23) so

F = .44 N

You would need to apply a force of 0.437 Newtons to the ball in order to achieve the desired acceleration of 23 m/s².

Force is a physical quantity that describes the interaction between objects or systems and their ability to change motion or shape. It is a vector quantity, meaning it has both magnitude and direction. Force can cause an object to accelerate, decelerate, or change direction.

According to Newton's second law of motion, force is directly proportional to the mass of an object and the acceleration it experiences. The equation F = m × a represents this relationship, where F is the force, m is the mass of the object, and a is the acceleration.

Force can be measured in various units, such as Newtons (N) in the International System of Units (SI) or pounds (lb) in the US customary system. Common examples of forces include gravity, friction, tension, compression, and applied forces like pushing or pulling an object.

According to Newton's second law of motion, which states that force (F) is equal to mass (m) multiplied by acceleration (a):

F = m × a

In this case, the mass of the ball is given as 0.019 kg, and the desired acceleration is 23 m/s². Plugging these values into the equation, we can calculate the force:

F = 0.019 kg × 23 m/s²

F = 0.437 kg m/s²

Learn more about Force, here:

https://brainly.com/question/30507236

#SPJ3

Explanation:

Optics is a branch of physics that is the study of light and vision. ... The branch of physics dealing with the nature and properties of electromagnetic energy in the light spectrum and the phenomena of vision. In the broadest sense, optics deals with infrared light, visible light, and ultraviolet light.

Answer:

the one above the surface of earth

Explanation:

earth has gravity the ball of the moon would float away

Answer:

(C) on edge.

Explanation:

Answer:

2.0

Explanation:

trust the process.

Answer:

a)  v₁ = - ½ v₂,  K₁ / K ₂ = ½,)

Explanation:

A) Let's use the conservation of the moment, for this we define the system formed by the spring and the two cars, so the force during the separation is internal, therefore the moment is conserved

initial instant. Before releasing the carts

         p₀ = 0

final instant. After jumping the cars

         p_f = M v₁ + m v₂₂

how the moment was preserved

        p₀ = p_f

        0 = M v₁ + m v₂

        v₁ = - m / M v₂

indicate that M = 2m

        v₁ = - ½ v₂

the kinetic energy of each car is

        K₁ = ½ M v₁²

        K₁ = ½ 2m (v₂/ 2) ²

        K₁ = m ₂v₂² / 4

        K₂ = ½ m v₂²

the relationship between the kinetic energies is

         K₁ / K₂ = ½

B) If the much greater than the mass of car 1 is mass of car 2

        v = - m / M v₂

         In this case, the speed of car 1 is very small, so the car 1 practitioner does not backtrack and car 2 leaves with a lot of speed.

The energy is still conserved, where almost all the energy has it is car 2

Answer:

Explanation:

We need the power equation here, which is:

Power = (F * Δx)/time

where F * Δx is the amount of work done.

F is a force which is measured in Newtons. We are given the mass of the object, but since we need a Force measure, we need the weight of the object:

F = 2100(9.0)

F = 21000 to the correct number of sig dig.

Now we can plug in the values we have and solve for the displacement, Δx:

[tex]45000=\frac{21000x}{17.4}[/tex] and isolating x:

[tex]\frac{17.4(45000)}{21000}=x[/tex] so

x = 37 m

Answer:

[tex]0.5\; \rm m^{3}[/tex].

Explanation:

Calculate the mass of this object:

[tex]\begin{aligned}& m(\text{object}) \\ &= \rho(\text{object}) \cdot V(\text{object}) \\ &= 500\; \rm kg \cdot m^{-3} \times 1\; \rm m^{3} = 500\; \rm kg\end{aligned}[/tex].

Multiple the mass of this object by the gravitational field strength, [tex]g[/tex], to find the weight of this object: [tex]W(\text{object}) = m(\text{object}) \cdot g[/tex].

Since this object is floating in water, the buoyancy force on it should be equal to its weight:

[tex]F(\text{buoyancy}) = W(\text{object}) = m(\text{object}) \cdot g[/tex].

By Archimedes' Principle, the weight of the water that this object displaces would be equal to [tex]F(\text{buoyancy})[/tex], the size of buoyancy force on this object,

Hence, the weight of water displaced would be [tex]W(\text{object}) = m(\text{object}) \cdot g[/tex].

Divide this weight by [tex]g[/tex] to find the mass of water displaced:

[tex]\begin{aligned} & m(\text{water displaced}) \\ &= \frac{W(\text{water displaced})}{g} \\ &= \frac{m(\text{object}) \cdot g}{g} = m(\text{object}) = 500\; \rm kg\end{aligned}[/tex].

Assume that the density of water is [tex]\rho(\text{water}) = 1000\; \rm kg \cdot m^{-3}[/tex]. The volume of water displaced would be:

[tex]\begin{aligned}& V(\text{water displaced}) \\ &= \frac{m(\text{water displaced})}{\rho(\text{water})} \\ &= \frac{500\; \rm kg}{1000\; \rm kg \cdot m^{-3}} = 0.5\; \rm m^{3}\end{aligned}[/tex].

Explanation:

that is my answer thank me later

Answer:

oxygen difluoride a polar molecule

Answer:

F=Gxy/r^2

Explanation:

F=Gm1m2/d^2

F=Gxy/r^2

Answer:

v = 37.59 km/h

Explanation:

The question says, "how fast in km / h did usain bolt run at the berlin world championship in 2009 to break the world record for the 100m sprint in 9.58".

Distance, d = 100 m = 0.1 km

Time, t = 9.58 s = 0.00266 h

We need to find the speed of the Usain Bolt. We know that,

Speed = distance/time

So,

[tex]v=\dfrac{0.1}{0.00266}\\\\v=37.59\ km/h[/tex]

So, the required speed is equal to 37.59 km/h.

Answer:

7)  λ = 0.5 m,  8)  f = 4.8 10¹⁴ Hz

Explanation:

The speed of an electromagnetic wave is

          c = λ f

where c is the speed of light in vacuum c = 3 10⁸ m / s

7) indicate the frequency f = 6.0 10⁸ Hz

we do not know the wavelength

         λ = c / f

we calculate

        λ = 3 10⁸ / 6.0 10⁸

        λ = 0.5 m

8) indicate the wavelength  λ = 6.25 10-7 m

we do not know the frequency

         f = c / λ

we calculate

        f = 3 10⁸ / 6.25 10⁻⁷

        f = 0.48 10¹⁵ Hz

        f = 4.8 10¹⁴ Hz

Explanation:

distance = velocity * time

d = 37.9 * 118

distance = 4472.2

Answer:

Yes, but only if it's sunny.

Explanation:

As you know, solar panels generate energy through the sun's rays of light (better known as sunlight). Therefore, as long as the sun is shining high in the sky, the car will generate electricity and be able to function. If this vehicle was only powered by solar panels, it would not function during the night, in cloudy areas, and/or in dark places (such as parking garages or home garages).

Hope this helps!

Well, let's see what we've got here:

                    ( 4⁻³ · 3⁴ · 4² )  /  ( 3⁵ · 4⁻² ) .

The two simple rules of exponents that we're

going to use here are:

-- Two multiply two numbers with the same base,

add their exponents.    Like   (A³) · (A²) = A⁵ .

But the bases have to be the same.

-- A negative power just means it belongs in the

other section of a fraction.

  A negative power on top means it belongs on the bottom.

  A negative power on the bottom means it belongs on top.

  Like    A⁻²  means  1/A² .  And  1/B⁻³  means  B³ .

That's all you need in order to clean up the big fraction

in the question.  But in order to see where you can use

these rules, you need to re-arrange things first.

Original:                          ( 4⁻³ · 3⁴ · 4² )  /  ( 3⁵ · 4⁻² )

Let's send the  4⁻³

to the bottom

where it belongs:              (   --  3⁴ · 4² )  /  4³ · ( 3⁵ · 4⁻² )

Not take that  4⁻² from

the bottom, and put it on

top, where it belongs:       (  4² · 3⁴ · 4² )  /  4³ · ( 3⁵    -- )

Multiply the 4²s on top:     (  4⁴ · 3⁴       )  /  ( 4³ · 3⁵ )

Now let me break this up.

Not changing anything, just

writing it in a different way:      ( 4⁴  /  4³ ) · ( 3⁴ / 3⁵ )

Look at the first fraction:  4⁴ / 4³ .

Divide top and bottom by  4³ , and it becomes just  4 .

Now look at the second fraction:  3⁴ / 3⁵ .

Divide top and bottom by  3⁴ , and it becomes just  1/3 .

So in the end, we're left with just      4 / 3 .

And THAT is exactly equal to the original big messy fraction

in the question.  It has exactly the same numerical value, but

you'd never know it when you see it, because it's a lot simpler.

There are a lot of other ways we could have manipulated and

massaged the original fraction, but the steps are the same:

-- Multiply numbers with the same base, by adding the exponents.

-- Remember that a number with a negative exponent belongs

in the other section of the fraction, with a positive exponent.

Explanation:

we know that

v = m/d

or; v=1kg/800kgm^3

or; v=0. 00125m

Answer:

hi

Explanation:

it is probably 12 m on the surface of the moon

have a good day

I hope this is help full to you

Answer:

The answer is A. A transistor

Answer:

a transistor

Explanation:

A P E X

Answer:

The horizontal component of the vector is approximately -16.07

The vertical component of the vector is approximately 19.15

Explanation:

A vector quantity is a quantity that posses both magnitude and direction specifications

The magnitude of the given vector, R = 25 units

The direction of the vector, θ = 130°

Therefore the location of the vector, starting from the origin of the Cartesian plane, is in the second quadrant having an angle of 180° - 130° = 50° to the horizontal

Given that the x-coordinate  is negative in the second quadrant, we have;

The horizontal component of the vector, Rₓ = The x-coordinate of the vector = R×cos(θ)

∴ The horizontal component of the vector, Rₓ = 25 × cos(130°) = -25 × cos(50°) ≈ -16.07

The horizontal component of the vector, Rₓ ≈ -16.07

The vertical component of the vector, [tex]R_y[/tex] = The y-coordinate of the vector = R×sin(θ)

∴ The vertical component of the vector, [tex]R_y[/tex] = 25 × sin(130°) ≈ 19.15

The vertical component of the vector, [tex]R_y[/tex] ≈ 19.15

The vector can be resolved as R = -16.07·i + 19.15·j

Answer:

hi

Explanation:

Answer:

To decrease the current;

1) Use fewer loops or number of turns

2) Use a lower speed of rotation of the coil in the magnetic field

3) Use a weaker magnetic

Explanation:

According to Faraday's Law of induction, which is the basis of the electromagnetism, electromagnetic induction and therefore the basis of the  electric generator, can be written as follows;

[tex]\epsilon = -N \cdot \dfrac{\Delta \phi}{\Delta t}[/tex]

Where;

ε = The induced voltage

N = The number of turns (loops)

ΔФ = The change in the magnetic flux

Δt = The change in the time (the duration)

Given that voltage is directly related to the current, decreasing the voltage, decreases the current

To decrease the voltage, and therefore, the current we can;

1) Reduce the number of loops in the coil

2) Increase the time change per unit change in flux by slowing down the speed of rotation of the generator

3) Decrease the amount of change in the magnetic field per turn, by using a weaker magnetic

Answer:

weight of rod =weight of liquid displaced

mass of the rod ×g =mass of liquid displaced ×g

(g cancelled out)

mass of the rod =mass of liquid displaced

density of rod ×volume of rod =density of liqiud ×volume of liquid displaced

O×cross section area of rod ×height of rod =density of liquid ×Cross section area of rod ×height of rod under the surface

O×L=density of liquid ×(L-h)

then density of liquid =OL/(L-h) shown as required

The density of the liquid is given by =OL/L − h

Density is the ratio of mass of an object and its volume.

According to the Archimedes principle, weight of rod = weight of liquid displaced

mass of the rod ×g =mass of liquid displaced ×g

So, mass of the rod =mass of liquid displaced

Mass in terms of density is substituted,

density of rod × volume of rod =density of liquid ×volume of liquid displaced

O× cross section area of rod ×height of rod =density of liquid ×Cross section area of rod ×height of rod under the surface

O×L=density of liquid ×(L-h)

Then, density of liquid =OL/(L-h).

Learn more about density.

https://brainly.com/question/9215083

#SPJ2

Answer:

P = 2.33 kW

Explanation:

Given that,

Mass, m = 200 kg

It is raises in the well from a depth of 7 m in 6 s.

W e know that,

Power = work done/time

Put all the values,

[tex]P=\dfrac{mgh}{t}\\\\P=\dfrac{200\times 10\times 7}{6}\\\\P=2333.3\ W[/tex]

or

P = 2.33 kW

Hence, the power of the engine is 2.33 kW.

Answer:

PLEASE MARK ME AS A BRAINLIEST

Explanation:

There are slight variations in the value of g about earth's surface. These variations result from the varying density of the geologic structures below each specific surface location. They also result from the fact that the earth is not truly spherical; the earth's surface is further from its center at the equator than it is at the poles. This would result in larger g values at the poles. As one proceeds further from earth's surface - say into a location of orbit about the earth - the value of g changes still.

Answer:

Its B

Explanation:

a p e x

Answer:

The pressure exerted by the girl is 245,000 N/m²

Explanation:

Given;

mass of the girl, m = 50 kg

area of the girl's shoe, A = 0.002 m²

The pressure exerted by the girl is calculated as follows;

[tex]P = \frac{F}{A} \\\\Where;\\F \ is \ the \ force \ exerted \ by \ girl's \ weight\\\\P = \frac{F}{A} = \frac{mg}{A} = \frac{50 \times 9.8}{0.002} = 245,000 \ N/m^2[/tex]

Therefore, the pressure exerted by the girl is 245,000 N/m²

Answer: A.

Explanation:

Máquina térmica tem como função, manter a temperatura de um dado fluído, então, a quantidade de calor desse mesmo fluído ao entrar na máquina, será igual á quantidade de calor desse fluido saindo.

Qin - Qout describes the work done by a heat engine. Hence option A is correct.

A heat engine is a system which converts heat into useful work. Carnot engine is  an ideal engine which has maximum efficiency than any other engines. Carnot has showed that "no engine can be more efficient than Carnot engine and the 100% efficient engine can not be existed". It takes heat from the reservoir to do some work and it discharges some amount of heat to the sink. Reservoir is know as hot body and sink is know as cold body.

Efficiency of the Carnot's heat engine is given by,

Efficiency, η = Work done / Heat input

Work done, W = Q1 – Q2

Heat input = Q1

Efficiency,

η = W / Q1

= (Q1 – Q2) / Q1

=1 – (Q2 / Q1).

To have engine with 100% efficiency, Q2 must be zero and it is not possible.

Hence work done by a heat engine is Qin - Qout.

To know more about heat engine, click :

https://brainly.com/question/28034387

#SPJ7.