Calculate the extension of a 20cm spring that has a spring contrast of 45000N/m and 1500N of elastic potential energy.

Answer:

6.4m/s

Explanation:

The total mechanical energy of the man is 1780J.

This mechanical energy is the energy due to the motion of the body and it is a form of kinetic energy.

 Also, mass  = 87kg

   Kinetic energy  = [tex]\frac{1}{2}[/tex]   m v²

m is the mass

v is the velocity

           1780  =  [tex]\frac{1}{2}[/tex] x 87 x v²

                v²  = 40.9

                v  = 6.4m/s

Answer:

[tex]|v|(t)=\sqrt{v_{x}^{2}(t)+v_{y}^{2}(t)+v_{z}^{2}(t)}=C[/tex]

[tex]2v(t)\cdot \frac{dv(t)}{dt}=0[/tex]

[tex]v(t)\cdot a(t)=0[/tex]

Explanation:

Let's start with the definition of a constant velocity.

If the velocity magnitude, in three dimensions,  is a constant value (C) we have a constant velocity, which means.

[tex]|v|(t)=\sqrt{v_{x}^{2}(t)+v_{y}^{2}(t)+v_{z}^{2}(t)}=C[/tex]

Now, we know that the dot product between v(t) and v(t) is the |v|².

[tex]v(t)\cdot v(t)=|v|^{2}(t)[/tex]

If we take the derivative whit respect to time in both sides of this equation we will have:

[tex]\frac{d}{dt}(v(t)\cdot v(t))=\frac{d}{dt}|v|^{2}(t)[/tex]

We apply the product rule on the left side and the right side will zero because the derivative of a constant is 0.

[tex]\frac{dv(t)}{dt}\cdot v(t)+v(t)\cdot \frac{dv(t)}{dt}=0[/tex]

[tex]2v(t)\cdot \frac{dv(t)}{dt}=0[/tex]

We know that dv(t)/dt = a(t) (using the acceleration definiton)

Therefore, we conclude:

[tex]v(t)\cdot \frac{dv(t)}{dt}=0[/tex]

[tex]v(t)\cdot a(t)=0[/tex]

If the dot product is 0, it means that v(t) and a(t) are orthogonal.

I hope it helps you!

Answer:

v= -107.8 m/s

Explanation:

       [tex]v_{f} = v_{o} + a*t = a*t = -g*t = 9.8m/s2*11s = -107.8 m/s (1)[/tex]

Answer:

D. wave one has a lower pitch

Explanation:  because The sound an object makes changes depending on how fast it is vibrating. When an object vibrates quickly, high-pitched sounds are heard. Low-pitched sounds come from things that vibrate more slowly.

Answer:

5m/s²

Explanation:

Given parameters:

Mass of refrigerator  = 50kg

Applied force  = 300N

Frictional force  = 50N

Unknown:

Acceleration of the refrigerator  = ?

Solution:

To solve this problem:

  Net force = m x a

  m is the mass

   a is the acceleration

 Net force  = Applied force  - Frictional force

             300  - 50  = 50 x a

                   250  = 50 x a

                    a  = 5m/s²

Answer:

Q1: (a)

[tex]1cm \: = 10 {}^{ - 2}m[/tex]

so

[tex]45 \times {10}^{ - 2} m[/tex]

Q2:

[tex]1km = 10 {}^{3} m \\ 6378km \times {10}^{ 3} [/tex]

this is the radius in meter

diameter = 2r

in this i don't know which choice is the right answer

Q3:

[tex]1gram = \: {10}^{ - 3} kg[/tex]

so

[tex]250 \times {10}^{ - 3} = 2.5 \times {10}^{ - 1} kg[/tex]

again there is no correct answer

Answer:

a) They are the same.

Explanation:

Assuming no friction, there should be no energy transfer and thus the Law of Conservation of Energy says:

[tex]PE=KE,\\mgh=\frac{1}{2}mv^2[/tex]

These types of problems also disregard any air resistance the surface of the object may cause. Therefore, no energy is transferred and from the Law of Conservation of Energy, [tex]100\%[/tex] of energy is preserved.

Answer:

why compasses point towards the north and south poles of the earth.

Explanation:

hope it helps!!

Answer:

[tex]375\:\mathrm{N}[/tex]

Explanation:

Work is given by the equation [tex]W=F\Delta x[/tex]. Plugging in given values, we get:

[tex]W=75\cdot 5=\fbox{$ 375\:\mathrm{N}$}[/tex].

Answer:

A battery works because of the electrical energy inside of the battery, which is connected through a wire, which transmits energy through the metal inside of the wire to power to object that the wire is connected to.

Explanation:

Answer:

because they are the rocks that line the surface of our planet ​

Explanation:

We see sedimentary rocks more than other rock types because they are the rocks that line the surface of our planet.

Sedimentary rocks typically form the earth cover due to the way they are formed.

Answer:

the Indian Ocean on 26 December 2004. This event claimed 227,898 dead and missing from 14 countries. The difference in mortality rates between these tsunamis reflects, in part, the benefits of understanding how tsunami waves are generated and move, and educating citizens to make scientifically

sound and potentially life-saving decisions.

A tsunami is a series of rapidly propagating, shallow-water ocean waves that develops when a submarine earthquake, landslide, or volcanic eruption displaces a large volume of water. Powerful earthquakes, with magnitudes of 9 or greater, caused both the 2004 and 2011 tsunamis. The earthquakes resulted from the movement of large tectonic plates. The 11 March 2011 earthquake occurred at 32 km (20

mi.) deep in Earth’s crust about 130 km (81 mi.) east of the city of Sendai. This location is on the boundary between two tectonic plates—the Pacific plate to the east and North American plate to the west. This

boundary fractured, releasing energy that was transmitted through the rocks and elevated portions of the

ocean floor. This drastic movement transmitted energy to the overlying ocean water, which generated

tsunami waves that radiated outward. The waves washed over the nearby coastlines and were felt around

the globe within hours (Figure 1.1).  

Explanation:

Answer:

I believe Geosphere (lithosphere) and Hydrosphere

Explanation:

I hope it's right if not please notify me.

Answer:

A)5524J,

B) 29.2Nm

Explanation:

This question can be treated using work- energy theorem

Work= change in Kinectic energy

W= Δ KE

Work= difference between the final Kinectic energy and intial Kinectic energy.

We know that

Kinectic energy= 1/2 mv^2 .............eqn(1)

This can be written in term of angular velocity, as

KE= 1/2 I

Answer:

the tack's tangential speed is  5.59 m/s

Explanation:

Given that;

R = 0.331 m

wheel rotates 2.69 times a second which means, the wheel complete 2.69 revolutions in a second, so

ω = 2.69 rev/s × 2π/1s = 16.9 rad/s

using the relation of angular speed with tangential speed

tangential speed v of the tack is expressed as;

v = R × ω

so we substitute

v = 0.331 m × 16.9 rad/s

v = 5.59 m/s

Therefore, the tack's tangential speed is  5.59 m/s

Answer:

B.

Explanation:

Answer:

7000J

Explanation:

Given parameters:

Mass of car  = 1400kg

Initial speed  = 10m/s

Final speed  = 20m/s

Unknown:

Amount of work done  = ?

Solution:

In this problem, the amount of work done is the same as the change in kinetic energy of the body.

So;

   Work done  = Final kinetic energy  - initial kinetic energy

           Kinetic energy  = [tex]\frac{1}{2}[/tex]  m v²

   Work done  = [tex]\frac{1}{2}[/tex]  m(V²f - V²i )

m is the mass

vf is the final velocity

vi is the initial velocity

   Work done  =  [tex]\frac{1}{2}[/tex] x 1400 x (20 - 10)  = 7000J

Answer:

Assuming the speed of sound in air is 345 m/s, determine the wavelength of this infrasonic sound wave. Let λ = wavelength. Use v = f • λ where v = 345 m/s and f = 10 Hz.

Explanation:nothing is my explanation lol

The sound wave does not damage the air because no external factors such as reflection, amplification, and vibrations are present. However, in the launch pad factors such as reflection, amplification, and vibrations are present which damages the sound wave.  

Closeness to the Sound Source: When a rocket is fired on the launchpad, it creates a tremendous amount of noise in proximity to the nearby equipment and structures.

When a rocket is launched, concentrated sound waves are created that can seriously harm neighboring structures, especially if such structures are not built to handle such strong vibrations. In contrast, once a rocket is in the air, the sound waves spread out and become less forceful as they travel through the atmosphere, decreasing the possibility that they may cause harm.

Reflection and Amplification: The launchpad environment can serve as an echo chamber for sound waves because of its huge, solid structures.

Hence, The sound wave does not damage the air because no external factors such as reflection, amplification, and vibrations are present. However, in the launch pad factors such as reflection, amplification, and vibrations are present which damages the sound wave.  

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Answer:

ΔP = 3.98 10³ Pa

Explanation:

We use that the pressure is given

          P = ρ g y

where ρ is the density of mercury (ρ = 13534 kg / m³) and y the height of the column

In this case, to measure the pressure, a line is drawn at the lowest point of the mercury column, on the right side of the U-shaped tube, for this point the pressure on both sides of the tube is the same

           ΔP = P_l{eft} - P_{right}

           ΔP = (P_a + P) - P_a

done P is the gauge pressure on the left side and P_a is the atmospheric pressure

          ΔP = ρ g h

let's calculate

          ΔP = 13534   9.8  0.03

          ΔP = 3.98 10³ Pa

remember that [Pa] = [N / m²]

Answer:

som,eythiung did cant wait

Explanation:

ya so i texted maria and she said i con c()me over so letyeyey yeah betty letty

PAINN I MISS JUOICE WORLDD PAINNNN

1 mA = 0.001 A

Therefore, 5 mA = 0.001 * 5

=0.005 A

Resistance = voltage / current

= 100 / 0.005

= 20000 ohms

Current = voltage / resistance

= 25 / 20000

= 0.00125 A (or) 1.25 mA

Answer:

B

Explanation:

on edge

The illustration with a vector pointed right going through an opening in a boundary and turning into a transverse wave on the other side demonstrates the phenomenon of absorption, so, option B is correct.

Absorption, in wave motion, is the process by which a wave's energy is transferred to matter when the wave travels through it. The energy of an electromagnetic, acoustic, or other wave is related to the square of its amplitude, which is the maximum displacement or movement of a point on the wave.

The amplitude of a wave continuously diminishes as it travels through a substance. The medium is described as being transparent to a specific type of radiation if just a tiny portion of the energy is absorbed, whereas it is described as opaque if all the energy is lost.

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Answer;

-54ft/s

y = -4/5 x + 10

Explanation

Given the position of an object expressed by the function

s(t)=−16t²+10t+100

Velocity is the change in position with respect to time

v(t) = ds(t)/dt

v(t) = -32t + 10

When t = 2

v(2) = -32(2)+10

v(2) = -64+10

v(2) = -54

Hence the velocity of the object is -54ft/s

b) The standard equation of a line in point slope form is expressed as;

y = MX+c

M is the slope

c is the y-intercept

Given the coordinate (5, 6) and (10, 2)

M = 2-6/10-5

M = -4/5

Get the y-intercept

Substitute m = -4/5 and any point say (5,6) into the expression y = mx+c

6 = -4/5 (5) + c

6 = -4+c

c = 6+4

c = 10

Get the required equation

Recall that: y = mx+c

y = -4/5 x + 10

Hence the equation of a line, in slope-intercept form is y = -4/5 x + 10

It will accelerate. A force of magnitude F exerted on an object of mass m applies an acceleration a according to

F = m a

Remember that force and accleration are vector quantities, so the object's acceleration would point in the same direction as the applied force. The other choices describe some possible outcomes, but

• it the object starts in motion, it can only stop moving if the force opposes the motion and acts in the opposite direction. The object would eventually stop, but only for an instant before changing direction and starting to move again. Consider a ball being thrown directly upward, reaching its highest point, then falling again.

• its speed (which is a scalar quantity) would only decrease if the object starts in motion and is slowed down. But if it starts at rest, its speed can only increase. Consider a ball being dropped from some height and gaining speed as it falls.

• its velocity will certainly change, but can only increase if the object is at rest, or if it's already in motion and the force points in the same direction.

Answer:

It will accelerate.

Explanation:

i go to K12

Answer:

Explanation:

The change in momentum is in the negative direction.

Answer:

D.

Explanation:

im guessing.

Answer: thermal conductivity

The difference in the rate at which these two materials transfer thermal energy throughout the cups is known as thermal conductivity.

It is the rate where the heat is to be transferred from conduction via the cross section area of the unit with respect to the material at the time when the temperature should be gradient and existed with the perpendicular to the area.

Also, in this, two material is to be transferred via the thermal energy with the help of cups.

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