Energy Transformation
A car with a mass of 2000 kg is traveling down the highway at a constant 20 m/s. How much kinetic energy does it have?
100 J
50 J
400.000 J
40.000 J

Answer:

1.(c) 7

2.(d) 900

3.(b) two

4.(c) 0.0007

5.(d)0.0004

Explanation:

(1) White light after reflection through prism splits into 7 colors.

(2) Arabs and Chinese knew about lenses in about 900 AD

(3) There are Two more colors in the spectrum which cannot be seen with naked eye.

(4) Wavelength of red light is 0.0007mm

(5) Wavelength of violet light is 0.0004mm

Explanation:

Single slit diffraction

Diffraction is the phenomenon of spreading out of waves as they pass through an aperture or around objects. Diffraction occurs when the size of the aperture or obstacle is of the same order of magnitude as the wavelength of the incident wave. For very small aperture sizes, the vast majority of the wave is blocked. in case of  large apertures the wave passes by or through the obstacle without any significant diffraction.

Answer:

The tension in the string is 52.89 N.

Explanation:

Given;

mass of the string, m = 19.1 g = 0.0191 kg

length of the string, L = 1.95 m

⇒mass per unit length, μ = 0.0191 / 1.95 = 0.009795 kg/m

Also Given;

frequency of the string, F = 440 Hz

wavelength of the sound wave, λ = 16.7 cm = 0.167 m

⇒the speed of the wave, v = Fλ = 440 x 0.167 = 73.48 m/s

The tension T in the string is calculated as;

[tex]v = \sqrt{\frac{T}{\mu} } \\\\v^2 = \frac{T}{\mu}\\\\T = v^2 \mu\\\\T = (73.48)^2 (0.009795)\\\\T = 52.89 \ N[/tex]

Therefore, the tension in the string is 52.89 N.

Answer:

E = 5.65 x 10¹⁰ N/C

Explanation:

First we need to find the total charge on the sphere. So, we use the following formula for that purpose:

[tex]q = \sigma V\\[/tex]

where,

q = total charge on sphere

V = Volume of Sphere = [tex]\frac{4}{3} \pi r^3 = \frac{4}{3} \pi (0.08\ m)^3 = 0.335\ m^3[/tex]

σ = volume charge density = 1.5 C/m³

Therefore,

[tex]q = (0.335\ m^3)(1.5\ C/m^3) \\q = 0.502 C[/tex]

Now, we use the following formula to find the electric field due to this charged sphere:

[tex]E = \frac{kq}{r^2}[/tex]

where.

E  = Electric Field Magnitude = ?

k = Coulomb's Constant = 9 x 10⁹ N.m²/C²

r = radius of sphere = 8 cm = 0.08 m

Therefore,

[tex]E = \frac{(9\ x\ 10^9\ Nm^2/C^2)(0.502 C)}{(0.08\ m)^2}\\\\[/tex]

E = 5.65 x 10¹⁰ N/C

Answer:

speed before landing = 3.9 m/s    (3 s.f.)

Explanation:

As rock is released from rest, u = 0 m/s     a = 1.62 m/s²     t = 2.4 s     v = ?

                      v = u + at

                      v = 0 + (1.62 x 2.4)

                      v = 3.888 = 3.9 s    (3 s.f.)

Hope this helps!

The speed of the rock before hitting the ground is 3.89 m/s

The given parameters;

acceleration due to gravity on moon, g = 1.62 m/s²

time taken for the object to fall, t = 2.4 s

To find:

The maximum height of fall of the rock is calculated as;

[tex]h = v_0t + \frac{1}{2} gt^2\\\\v_0 = 0\\\\h = \frac{1}{2} gt^2\\\\h = 0.5 \times 1.62 \times 2.4^2 \\\\h = 4.67 \ m[/tex]

The speed of the rock before hitting the ground is calculated as;

[tex]v_f^2 = v_0 ^2 + 2gh\\\\v_f^2 = 0 + 2\times 1.62 \times 4.67\\\\v_f^2 = 15.13\\\\v_f = \sqrt{15.13} \\\\v_f = 3.89 \ m/s[/tex]

Thus, the speed of the rock before hitting the ground is 3.89 m/s

Learn more here: https://brainly.com/question/4617423

Answer:

T large = 3T small

Explanation:

It's just 3 times larger

Answer:

Explanation:

A supersonic aircraft flies at 3 km altitude at a speed of 1000 m/s on a standard day. How long after passing directly above a ground observer is the sound of the aircraft heard by the ground observer

Using the formula for calculating speed expressed as;

Speed = Distance/Time

Given;

Distance = 3km = 3000m

Speed = 1000m/s

Required

How long after passing directly above a ground observer is the sound of the aircraft heard by the ground observer (Time)

From the formula;

Time = Distance/speed

Time = 3000/1000

Time = 3seconds

Hence the sound of the aircraft is heard after 3 seconds

Answer:

1962 joules

Explanation:

m = 10 kg

h = 20 m

g = 9.81 ms^-2

PE = ?

PE = MGH

PE = 10 x 9.81 x 20

PE = 1962 joules

Answer:

hiiiiiiiiiiiii baby.........

Answer:

the answer may be mass and distance

Answer:

same for all objects

Explanation:

earth pulls every object by same force of gravity

Answer:

The skier will be moving at 13.31 m/s.

Explanation:

To calculate the velocity of the skier we need to find the acceleration, as follows:

[tex] \Sigma F = ma [/tex]

[tex] F_{r} - F_{f} = ma [/tex]

Where:

[tex] F_{r}[/tex]: is the force due to the rope = 365 N

[tex] F_{f}[/tex]: is the combined average frictional force = 190 N

m: is the mass = 75.0 kg

[tex] a = \frac{365 N - 190 N}{75.0 kg} = 2.33 m/s^{2} [/tex]

Now, we can calculate the velocity of the skier by using the following kinematic equation:

[tex] v_{f}^{2} = v_{0}^{2} + 2ad [/tex]

Where:

[tex] v_{f}[/tex]: is the final velocity =?

[tex] v_{0}[/tex]: is the initial velocity = 0 (the skier is initially at rest)

d: is the distance = 38.0 m

[tex] v_{f} = \sqrt{2*2.33 m/s^{2}*38.0 m} = 13.31 m/s [/tex]

Therefore, the skier will be moving at 13.31 m/s.

I hope it helps you!                                                                                  

Answer:

[tex]K.E = (\frac{1}{2})Pv[/tex]

Explanation:

The momentum of a particle is defined as the product of its mass and velocity:

[tex]P = mv[/tex]   -------------------- equation (1)

where,

P = momentum of the particle

m = mass of the particle

v = velocity of the particle

The kinetic energy of the particle is given as follows:

[tex]K.E = (\frac{1}{2})mv^2\\\\K.E = (\frac{1}{2})v(mv)[/tex]

using equation (1), we get:

[tex]K.E = (\frac{1}{2})Pv[/tex]

Given that,

Mass of student 1, m₁ = 90 kg

Mass of student 2, m₂ = 60 kg

Speed of student 1, v₁ = 5 m/s

To find,

The velocity of the other student.

Solution,

Using the conservation of momentum to find the velocity of the other student. Let it is v₂.

[tex]m_1v_1=m_2v_2\\\\v_2=\dfrac{m_1v_1}{m_2}\\\\v_2=\dfrac{90\times 5}{60}\\\\=7.5\ m/s[/tex]

So, the velocity of the other student is 7.5 m/s.

Given that,

Mass of a sprinter = 70 kg

Initial velocity, u = 0

Final velocity, v = 10 m/s

Time, t = 3 s

To find,

Power output.

Solution,

The work done by the sprinter is equal to its kinetic energy.

[tex]W=\dfrac{1}{2}m(v^2-u^2)\\\\=\dfrac{1}{2}\times 70\times 10^2\\\\=3500\ J[/tex]

Let P is power output. Power is equal to work done per unit time. So,

[tex]P=\dfrac{3500\ J}{3\ s}\\\\=1166.67\ W[/tex]

So, the power output is 1166.66 W.

Answer:

A, Magnetism

Explanation:

An ordinary electric generator produces electric power by spinning a strong magnet inside a set of wire coils. As the magnet spins, its magnetic field sweeps across the coils and gives rise to electric fields in those coils.

Hope this helps!!

Answer: because of friction it will stop rolling completly

Explanation:

Given that,

At 3.00 m from a source that is emitting sound uniformly in all directions, the sound level is 60.0 dB.

To find,

The distance from the source would the sound level be one-fourth the sound level at 3.00 m.

Solution,

The intensity from a source is inversely proportional to the distance.

Let I₁ = 60 dB, r₁ = 3 m, I₂ = 60/4 = 15 dB, r₂ =?

Using relation :

[tex]\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}\\\\r_2^2=\dfrac{I_1r_1^2}{I_2}\\\\r_2^2=\dfrac{60\times (3)^2}{15}\\\\r_2=6\ m[/tex]

So, at a distance of 6 m the sound level will be one fourth of the sound level at 3 m.

Answer:

48,2 m/s²

Explanation:

We're gonna use the Centripetal Acceleration formula: v² / r but before that, we got to know the velocity, that is not shown clearly to us, so....

To know the velocity let's calculate the distance that the ball traveled

The circumference of a circle formula is:

2piR

2 . 3,14 . 7,1 | That is equal to 44,588 m

We know that the ball traveled this distance 3,9 times, so...

44,588 . 3,9 = 173,8932 m

Ok, now we have the distance, just need to know the time, that is 9.4 seconds.

Velocity = Distance / Time

V = 173,8932 / 9,4

V = 18,5 (approximate)

So...

We are back to the first formula:

Ca = v² / r

Ca = 18,5² / 7.1

Ca = 48,2 m/s² (approximate)

I hope it is correct, hahaha.

Answer:

A

Explanation:

When coal is burned it releases many harmful chemicals into the air, such as methane (greenhouse gas) and contributes to global warming

Answer:

v = 1247.92 m/s

Explanation:

The formula for kinetic energy is given as follows:

[tex]K.E = \frac{1}{2}mv^2[/tex]

Another formula that is used for Kinetic Energy is given as:

[tex]K.E = \frac{3}{2}KT[/tex]

Comparing both formulae for K.E:

[tex]\frac{1}{2}mv^2 = \frac{3}{2}KT\\\\mv^2 = 3KT\\v = \sqrt{ \frac{3KT}{m}}[/tex]

where,

v = rms speed of helium molecule = ?

K = Boltzmann Constant = 1.38 x 10⁻²³ J/k

T = Absolute Temperature = 250 K

m = mass of helium molecule = 6.646 x 10⁻²⁷ kg

Therefore,

[tex]v = \sqrt{\frac{(3)(1.38\ x\ 10^{-23}\ J/k)(250\ k)}{6.646\ x\ 10^{-27}\ kg}} \\\\[/tex]

v = 1247.92 m/s

Answer:

magma

Explanation:

I wanna think that that's right if it's not in so sorry but I'm pretty sure it's magma

Intrusive magma forced up towards the ocean ridge is the force responsible for seafloor spread. The correct option is B.

Seafloor spreading is a process that occurs at mid-ocean ridges where the oceanic crust is produced by volcanic activity and then moves away from the ridge.

Plate tectonics' continental drift is explained by seafloor spreading. When oceanic plates diverge, tensile stress causes fractures in the lithosphere.

Ridge push occurs when plates are not subducting and are driven by gravity as they slide off the elevated mid-ocean ridges.

Magma rises from the fractures at a spreading center and cools on the ocean floor to form a new seabed.

The spreading rate is the rate at which an ocean basin widens due to seafloor spreading and determines whether the ridge is fast, intermediate, or slow.

Thus, the correct option is B.

For more details regarding seafloor spreading, visit:

https://brainly.com/question/15122129

#SPJ6

Answer:

B) Schizophrenia

Explanation:

Hope this helps!

Answer:D

Explanation:If you want to find the acceleration do Force/mass.

The greatest magnitude of acceleration is of 20 m/s², by the student of 50 kg pushing the chair with 1000 N of force. Hence, option (D) is correct.

As per the Newton's second law, " The applied force on an object is equal to the product of mass of object and acceleration cause by the applied force. Then, the mathematical expression is,

F = ma

Here, F is the applied force, m is the mass and a is acceleration.

(A)

For 20 kg mass and 100 N force, the acceleration is,

F = ma

100 = (20)a

a = 5 m/s²

(B)

For 10,000 kg mass of rocket and 100,000 N force, the acceleration is,

F = ma

100 ,000= (10,000)a

a = 10 m/s²

(C) For a 2,000 kg mass of car and force of 1000 N, the acceleration is,

F = ma

1000 = (2000)a

a = 0.5 m/s²

(D) For a mass of 50 kg student and applied force of 1000 N, the acceleration is,

F = ma

1000 = (50)a

a =20 m/s².

Thus, we can conclude that the greatest magnitude of acceleration is of 20 m/s², by the student of 50 kg pushing the chair with 1000 N of force. Hence, option (D) is correct.

Learn more about the Newton's Second law here:

https://brainly.com/question/13447525

Answer:

17.71N/m

Explanation:

The period of the spring is expressed according to the expression;

[tex]T = 2 \pi \sqrt{\frac{m}{k} } \\[/tex]

m is the mass of the object

k is the force constant

Given

m = 5.50kg

T = 3.50s

Substitute into the formula;

[tex]T = 2 \pi \sqrt{\frac{m}{k} } \\3.5 = 2 (3.14) \sqrt{\frac{5.5}{k} } \\3.5 = 6.28 \sqrt{\frac{5.5}{k} } \\\frac{3.5}{6.28} = \sqrt{\frac{5.5}{k} } \\0.557 = \sqrt{\frac{5.5}{k} } \\square \ both \ sides\\0.557^2 = (\sqrt{\frac{5.5}{k} })^2 \\0.3106 = \frac{5,5}{k}\\k = \frac{5.5}{0.3106}\\k = 17.71N/m[/tex]

Hence the force constant of the spring is 17.71N/m

Answer:

[tex]v_{PB} = 130\ km/h[/tex]

Explanation:

Since, Alex is at rest. Therefore, the speed measured by him will be the absolute speed of car P. Therefore, taking easterly direction as positive:

[tex]Absolute\ Velocity\ of\ Car\ P = v_{P} = -78\ km/h[/tex]

And the absolute velocity of Barbara's Car is given as:[tex]Absolute\ Velocity\ of\ Barbara's\ Car = v_{B} = 52\ km/h[/tex]

Now, for the velocity of Car p with respect to the velocity of Barbara's Car can be given s follows:

[tex]Velocity\ of\ Car\ P\ measured\ by\ Barbara = v_{PB} = v_{B}-v_{P}\\\\v_{PB} = 52\ km/h-(-78\ km/h)[/tex]

[tex]v_{PB} = 130\ km/h[/tex]

Answer:

W = - 118.24 J (negative sign shows that work is done on piston)

Explanation:

First, we find the change in internal energy of the diatomic gas by using the following formula:

[tex]\Delta\ U = nC_{v}\Delta\ T[/tex]

where,

ΔU = Change in internal energy of gas = ?

n = no. of moles of gas = 0.0884 mole

Cv = Molar Specific Heat at constant volume = 5R/2 (for diatomic gases)

Cv = 5(8.314 J/mol.K)/2 = 20.785 J/mol.K

ΔT = Rise in Temperature = 18.8 K

Therefore,

[tex]\Delta\ U = (0.0884\ moles)(20.785\ J/mol.K)(18.8\ K)\\\Delta\ U = 34.54\ J[/tex]

Now, we can apply First Law of Thermodynamics as follows:

[tex]\Delta\ Q = \Delta\ U + W[/tex]

where,

ΔQ = Heat flow = - 83.7 J (negative sign due to outflow)

W = Work done = ?

Therefore,

[tex]-83.7\ J = 34.54\ J + W\\W = -83.7\ J - 34.54\ J\\[/tex]

W = - 118.24 J (negative sign shows that work is done on piston)

Answer:

-49.2

Explanation:

Trust me bro

Answer:

Plane mirror

Explanation:

A virtual image is a copy of an object formed at the location from which the light rays appear to come.