An object's inertia is its tendency to maintain contact:

1.) Mass.
2.) Position.
3.) Acceleration.
4.) Velocity.

Answer:

The police car is moving at 41.24 m/s.

Explanation:

To find the speed of the police car we need to use the Doppler equation:

[tex] f = f_{0}(\frac{v + v_{r}}{v + v_{s}}) [/tex]      

Where:

v: is the speed of the sound = 343 m/s

[tex]v_{r}[/tex]: is the speed of the receiver = 12 m/s

[tex]v_{s}[/tex]: is the speed of the source =?

f: is the observed frequency = 959 Hz

f₀: is the emitted frequency = 1038 Hz          

Both terms are positive in the fraction because the velocity of the sound is in the opposite direction to both velocities of the police car and the other car.  

By solving the above equation for [tex]v_{s}[/tex] we have:        

[tex] v_{s} = \frac{f_{0}(v + v_{r})}{f} - v = \frac{1038(343 + 12)}{959} - 343 = 41.24 m/s [/tex]  

Therefore, the police car is moving at 41.24 m/s.

I hope it helps you!                  

Answer:

46.67 miles/s

Explanation:

...........

Answer:

I = 1.666... amps

Explanation:

P = I*V or Power = Current * Voltage

(100 watts) = I * (60 Volts)

I = 1.666... amps

Answer:

Stars i think

Explanation:

Answer:

convection currents in the earth's mantle, heat and pressure within the earth cause the hot magma to flow in convection currents. This causes the movement of the tectonic plates.

rift valley, Africa

plz mark me as brainliest

Answer:

Log burning in a fire. Burning wood is an example of a chemical reaction in which wood in the presence of heat and oxygen is transformed into carbon dioxide, water vapor, and ash.

Explanation:

Answer:

a) 500 J

Explanation:

Potential energy can be defined as an energy possessed by an object or body due to its position.

Mathematically, potential energy is given by the formula;

[tex] P.E = mgh[/tex]

Where,

P.E represents potential energy measured in Joules.

m represents the mass of an object.

g represents acceleration due to gravity measured in meters per seconds square.

h represents the height measured in meters.

In Science, the potential energy possessed by an object or body is the same as the work done by the object or body.

Since we know that the object possessed 500 Joules of potential energy; it would ultimately require to do a work of 500 Joules to lift the object.

Mathematically, work done = force * distance

But force = mass * acceleration due to gravity

F = mg; d = h

Substituting into the work done formula, we have;

Hence, Workdone = Fd = mgh

Answer:

Explanation:

Let the potential difference between the middle point and one of the plate be ΔV .

electric potential energy will be lost and it will be converted into kinetic energy .

Electrical potential energy lost = Vq , where q is charge on charge particle .

For proton

ΔV× q = 1/2 M V² ( kinetic energy of proton )

where M is mass and V be final velocity of proton .

For electron

ΔV× q = 1/2 m v² ( kinetic energy of electron  )

where m is mass and v be final velocity of electron . Charges on proton and electron are same in magnitude .

As LHS of both the equation are same , RHS will also be same . That means the kinetic energy of both proton and electron will be same

1/2 M V² =  1/2 m v²

(V / v )² = ( m / M )

(V / v ) = √ ( m / M )

In other words , their velocities  are  inversely proportional to square root of their masses .

Answer:

3 moles

Explanation:

Ratio of O2 to CO2 = 2 : 1 = 6 : 3

Answer:

It would be B.

Explanation:

Answer:

d=v1t - .5at^2

d=4.88 x .872 - 0.5 x (4.88/0.872) x 0.872^2

d=4.255 - 2.12

d= 2.135m

Explanation:

acceleration is negative because she is slowing down.

Answer:

im means into

e means out of

Explanation:

Using the definitions of immigration and emigration as points of reference, the following explanation applies.

Both terms are derived from migration which means moving from one place to another.

By further explanation:

The "im" in the definition of immigration means "into" while the "e" in the definition of emigration means "out of"

Alban Geissler, who developed the SKYRAY carbon fiber wing with Christoph Aarns, suggested after Baumgartner's jump that the wing he used was a copy of two prototype SKYRAY wings sold to Red Bull (Baumgartner's sponsor) two years earlier. - wiki

Answer:

Eventually the pressure in the core was so great that hydrogen atoms began to combine and form helium, releasing a tremendous amount of energy. With that, our Sun was born, and it eventually amassed more than 99 percent of the available matter

Explanation:

jouleeeee is the unit kinetic energy is measured in and kinetic energy formula is 1/2mv (square)

Answer & Explanation:

This can be explained with Newton's first law, Inertia - if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.  

When you walk, your entire body is in a forwarding motion. If your toe hits an object (in this case, a chair), only this unfortunate toe will stop while the rest of your body continues its forwarding motion, resulting in you falling forward.

Answer:

D !!!

Explanation:

Answer:

D

Explanation:

Answer:

Shear stress  is 50.63 Pascal

Explanation:

As we know shear stress = [tex]\frac{\rho V^2 f}{8} \\[/tex]

Rho is the density

V is the velocity

f is the value from Moody's chart

We will know determine Reynolds number  to determine the flow type and then the f value

[tex]R_e = \frac{ \rho*V*D}{u}[/tex]

[tex]R_e = \frac{1000*3*0.0254}{0.001} = 76200[/tex]

This is a turbulent flow and hence the roughness index is [tex]\frac{E}{D} = 0.0157[/tex], From this we get f = 0.045

Now shear stress = [tex]\frac{1000 * 3^2 * 0.045}{8} = 50.63[/tex] Pa

Answer:

a.16.125 N b. The force is an attractive force. c. 2.68 × 10¹³ electrons d. 3.75 × 10¹³ electrons

Explanation:

a. What is the magnitude of the electric force between the corks?

The electrostatic force of attraction between the two corks is given by

F = kq₁q₂/r² where k = 9 × 10⁹ Nm²/C², q₁ = +6.0 μC = +6.0 × 10⁻⁶ C, q₂ = -4.3 μC = -4.3 × 10⁻⁶ C and r = distance between the corks = 0.12 m

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

F = kq₁q₂/r²

F = 9 × 10⁹ Nm²/C² × +6.0 × 10⁻⁶ C × -4.3 × 10⁻⁶ C/(0.12 m)²

= -232.2 × 10⁻³ Nm²/(0.0144 m)²

= -16125 × 10⁻³ N

= -16.125 N

So, the magnitude of the force is 16.125 N

b. Is this force attractive or repulsive?

Since the direction of the force is negative, it is directed towards the positively charged cork, so the force is an attractive force.

c. How many excess electrons are on the negative cork?

Since Q = ne where Q = charge on negative cork = -4.3 μC = -4.3 × 10⁻⁶ C and n = number of excess electrons and e = electron charge = -1.602 × 10⁻¹⁹ C

So n = Q/e = -4.3 × 10⁻⁶ C/-1.602 × 10⁻¹⁹ C = 2.68 × 10¹³ electrons

d. How many electrons has the positive cork lost?

We need to first find the number of excess positive charge n'

Q' = n'q where Q = charge on positive cork = + 6.0 μC = + 6.0 × 10⁻⁶ C and n = number of excess protons and q = proton charge = +1.602 × 10⁻¹⁹ C

So n' = Q'/q = +6.0 × 10⁻⁶ C/+1.602 × 10⁻¹⁹ C = 3.75 × 10¹³ protons

To maintain a positive charge, the number of excess protons equals the number of electrons lost = 3.75 × 10¹³ electrons

Answer:

the answer is true.

Explanation:

hope it will help you

Answer:

it goes up until we help it to but the moment we stop support it gets affected by gravity and goes back

Explanation:

Answer:

Option B

Explanation:

As we know

Frequency (F) * wavelength (W) = C (speed of light - can also be taken as constant)

Hence,

[tex]F1 W1 = C\\F2W2 = C[/tex]

Or [tex]F1W1 = F2W2[/tex]

Substituting the given values, we get -

[tex]840 *2.5 = 500 *XX = 4.2[/tex] m

Hence, option B is correct

Answer:

Folk dance

Explanation:

hope i helped :)

Answer:

For which the reasoning of the boy is correct for small heights, but as height increases his analysis is not correct.

Explanation:

The force of gravity comes from Newton's second law with the force the universal attraction

         F = ma

         F = [tex]G \frac{m_1 M}{(R_e +h)^2}[/tex]

we substitute

          [tex]G \frac{m_1 M}{ (R_e+ h)^2}[/tex] = m₁ a

where Re is the radius of the Earth 6.37 106 m

          a = [tex]G\frac{M}{R_e^2} \ ( 1 + \frac{h}{R_e})^{-2}[/tex]

In general, the height is much less than the radius of the earth, therefore the term ha / Re is very small and we can use a series expansion leaving only the first fears.

             (1 + x)⁻² = 1 -2x + [tex]\frac{2 \ 1}{2!}[/tex]  x²

we substitute

          a = g₀ ([tex]1 - 2 \frac{h}{R_e}[/tex] )

with

         g₀ = [tex]G \frac{M}{R_e^2}[/tex]

let's launch the expression.

* For small height compared to the radius of the earth we can neglect the last term

          g = g₀

* For height comparable to the radius of the Earth

          g = g₀  [tex](1 - \frac{2h}{Re} )[/tex]

We see that the acceleration of gravity is decreasing.

For which the reasoning of the boy is correct for small heights, but as height increases his analysis is not correct.

The student's reasoning gone wrong when the analysis is undertaken for the increasing heights, to drop the object.

The given problem is based on the concept of gravity and gravitational force. The force of gravity comes from Newton's second law with the force the universal attraction as,

F = ma

[tex]F=G\dfrac{mM}{(R+h)^{2}}\\\\\\ma = G\dfrac{mM}{(R+h)^{2}}[/tex]

Here, a is the linear acceleration, m is the mass of object, M is the mass of Earth, R is the radius of Earth and h is the height from where the objects will be dropped. Then,

[tex]a = \dfrac{GM}{R^{2}} \times(1+h/R)^{-2}[/tex]

In general, the height is much less than the radius of the earth, therefore the term h/ R is very small, hence can be neglected.

[tex]a = \dfrac{GM}{R^{2}}\\\\a=g = \dfrac{GM}{R^{2}}[/tex]

g is the gravitational acceleration.

For small height compared to the radius of the earth we can neglect the last term as,

a = g

And for the height comparable to radius of Earth,

[tex]a = \dfrac{GM}{R^{2}} \times(1+h/R)^{-2}\\\\a=g \times(1+h/R)^{-2}[/tex]

Clearly, the acceleration of gravity is decreasing, for which the reasoning of the boy is correct for small heights, but as height increases his analysis is not correct.

Thus, we can conclude that the student's reasoning gone wrong when the analysis is undertaken for the increasing heights, to drop the object.

Learn more about the gravitational force here:

https://brainly.com/question/15647838

Answer: 98 kN/m

Explanation:

Given

Mass of elephant [tex]m=5000\ kg[/tex]

Spring compresses from [tex]1\ m\ (100\ cm) \text{to}\ 50\ cm[/tex]

i.e. change in length is [tex]100-50=50\ cm[/tex]

spring force is given by  [tex]kx[/tex]

where k=spring constant

x=change in length

The weight of elephant must be equal to the spring force

[tex]\Rightarrow W=kx\\\Rightarrow 5000\times 9.8=k\times 0.5\\\Rightarrow k=98,000\ N/m\ or\ 98\ kN/m[/tex]

Answer:

1.17 m

Explanation:

From the question,

s₁ = vt₁/2................ Equation 1

Where s₁ = distance of the reflecting object for the first echo, v = speed of the sound in air, t₁ = time to dectect the first echo.

Given: v = 343 m/s, t = 0.0115 s

Substitute into equation 1

s₁ = (343×0.0115)/2

s₁ = 1.97 m.

Similarly,

s₂ = vt₂/2.................. Equation 2

Where s₂ = distance of the reflecting object for the second echo, t₂ = Time taken to detect the second echo

Given: v = 343 m/s, t₂ = 0.0183 s

Substitute into equation 2

s₂ = (343×0.0183)/2

s₂ = 3.14 m

The distance moved by the reflecting object from s₁ to s₂ = s₂-s₁

s₂-s₁ =  (3.14-1.97) m = 1.17 m

Answer:

a unit of mass or weight equaling one thousand grams

Answer:

Velocity can be directly added or subtracted.

For example, if a boat has a velocity V in still water.

And now you put the boat in a river with a current that has a velocity V'

The total velocity of the boat in that river is just the addition of these two velocities.

Velocity in the river  = V + V'

Where the only tricky part is that the velocity is a vector, so you need to take in account the directions of each vector.

In this case, we have a plane with a maximum velocity of 160km, let's assume a direction for this velocity, let's say that is in the positive x-direction.

Then we can write the velocity in the vector form:

velocity  = (vel in x-axis, vel in y-axis)

The velocity of the plane can be written as:

v = (160km/h, 0)

Now we add a crosswind of 30km/h

crosswind means that it is perpendicular, then it acts on the y-axis.

Then the total velocity of the plane will be:

velocity = (160km/h, 0) + (0, 30km/h)

velocity = (160km/h, 30km/h)

Now you can compute the total velocity of the airplane as the module of that vector.

Remember that for a vector (x, y) the module is:

mod = √(x^2 + y^2)

Then the module of the velocity is:

v = √( (160km/h)^2 + (30km/h)^2) = 162.8 km/h