under what condition could the weight of an object equal zero

Answe16000/3500(-1.5-2-)225000= 1.1

Explanation:

The mass of the mixture will be 2.19 ×10⁻³ kg. The unit of mass is kg and it is a scalar quantity.

Mass is a numerical measure of inertia, which is a basic feature of all matter. It is, in effect, a body of matter's resistance to a change in speed or position caused by the application of a force.

In the International System of Units (SI), the kilogram is the unit of mass.

The given data in the problem is;

The initial temperature of the mixture was, [tex]\rm T_i = 20 ^0 \ C[/tex]

The mixture froze at the temperature of, [tex]\rm T_F = -1.5 ^0 \ C[/tex]

The internal energy is,[tex]\rm E = \rm 165 \ kJ[/tex]

The specific heat capacity of the mixture is,[tex]\rm C = 3500 J/kg ^0C[/tex]

The specific latent heat of fusion of the mixture is,[tex]\rm l = 255 000 J/kg[/tex]

m is the mass of the mixture,

The latent heat is equal to the heat transfer. Because the net work done is zero.

The formula for the heat transfer is found as;

[tex]\rm Q = mCdt \\\\ m = \frac{Q}{Cdt} \\\\ m = \frac{165 }{3500(20-(-1.5)} \\\\ m = 2.19 \times 10^{-3} \ kg[/tex]

Hence the mass of the mixture will be 2.19 ×10⁻³ kg.

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Answer:

c. lubricant..........

For the 100 kg roller coaster that comes over the first hill of height 20 meters at 2 m/s, we have:

1) The total energy for the roller coaster at the initial point is 19820 J

2) The potential energy at point A is 19620 J

3) The kinetic energy at point B is 10010 J

4) The potential energy at point C is zero

5) The kinetic energy at point C is 19820 J

6) The velocity of the roller coaster at point C is 19.91 m/s

1) The total energy for the roller coaster at the initial point can be found as follows:

[tex] E_{t} = KE_{i} + PE_{i} [/tex]

Where:

KE: is the kinetic energy = (1/2)mv₀²

m: is the mass of the roller coaster = 100 kg

v₀: is the initial velocity = 2 m/s

PE: is the potential energy = mgh

g: is the acceleration due to gravity = 9.81 m/s²

h: is the height = 20 m

The total energy is:

[tex] E_{t} = KE_{i} + PE_{i} = \frac{1}{2}mv_{0}^{2} + mgh = \frac{1}{2}*100 kg*(2 m/s)^{2} + 100 kg*9.81 m/s^{2}*20 m = 19820 J [/tex]

Hence, the total energy for the roller coaster at the initial point is 19820 J.

2) The potential energy at point A is:

[tex] PE_{A} = mgh_{A} = 100 kg*9.81 m/s^{2}*20 m = 19620 J [/tex]

Then, the potential energy at point A is 19620 J.

3) The kinetic energy at point B is the following:

[tex] KE_{A} + PE_{A} = KE_{B} + PE_{B} [/tex]

[tex] KE_{B} = KE_{A} + PE_{A} - PE_{B} [/tex]

Since

[tex] KE_{A} + PE_{A} = KE_{i} + PE_{i} [/tex]

we have:

[tex] KE_{B} = KE_{i} + PE_{i} - PE_{B} =  19820 J - mgh_{B} = 19820 J - 100kg*9.81m/s^{2}*10 m = 10010 J [/tex]

Hence, the kinetic energy at point B is 10010 J.

4) The potential energy at point C is zero because h = 0 meters.

[tex] PE_{C} = mgh = 100 kg*9.81 m/s^{2}*0 m = 0 J [/tex]

5) The kinetic energy of the roller coaster at point C is:

[tex] KE_{i} + PE_{i} = KE_{C} + PE_{C} [/tex]            

[tex] KE_{C} = KE_{i} + PE_{i} = 19820 J [/tex]      

Therefore, the kinetic energy at point C is 19820 J.

6) The velocity of the roller coaster at point C is given by:

[tex] KE_{C} = \frac{1}{2}mv_{C}^{2} [/tex]

[tex] v_{C} = \sqrt{\frac{2KE_{C}}{m}} = \sqrt{\frac{2*19820 J}{100 kg}} = 19.91 m/s [/tex]

Hence, the velocity of the roller coaster at point C is 19.91 m/s.

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Answer:

Mechanical energy is the energy a substance or system has because of its motion. For example machines use mechanical energy to do work.

Answer:

43 km/h

Explanation:

If the car is going past you at 50 km/h, then all the objects inside appear to be going 50 km/h. The fly is flying 7km/h in the opposite direction, and would appear to be going 7 km/h slower. Therefore, as 50 - 7 is 43, the fly would appear to be going 43 km/h. Hope this helps :D

Answer:

SONGS CLICKS AND WHISTLE

Explanation:

Answer:

please check the image

Explanation:

I hope this image helps you please follow the steps. Thank you

Answer:

1kg/```````2

Explanation:

solution

Answer:

6.7 km/h (C)

Explanation:

According to the table, the hiker's average speed for the entire hike would be 6.7 kilometers/hour.

The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object. The unit of speed is a meter/second. The generally considered unit for speed is a meter per second.

The total distance traveled by the hiker = 4 kilometers  + 6 kilometers + 4 kilometers west + 6 kilometers north

                                                                  = 20 kilometers

The total time is taken by the hiker = 45 min + 60 min + 30 min+ 45 min

                                                           = 180 min

                                                           =3 hours

The average speed of the hiker = 20 kilometers / 3 hours

                                                     = 6.7 kilometers / hours

Thus, the hiker's average speed for the entire hike would be 6.7 kilometers/hour.

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Answer:

Choice C: Approximately [tex]1.64[/tex].

(Assuming that light entered into this glass block from air.)  

Explanation:

Let [tex]n_{1}[/tex] denote the refractive index of the first medium (in this example, air.) Let [tex]\theta_{1}[/tex] denote the angle of incidence.

Let [tex]n_{2}[/tex] denote the refractive index of the second medium (in this example, the glass block.) Let [tex]\theta_{2}[/tex] denote the angle of refraction.

By Snell's Law:

[tex]n_{1} \, \sin(\theta_{1}) = n_{2}\, \sin(\theta_{2})[/tex].

Rearrange the equation to find an expression for [tex]n_{2}[/tex], the refractive index of the second medium (the glass block.)

[tex]\begin{aligned}n_{2} = \left(\frac{\sin(\theta_{1})}{\sin(\theta_{2})}\right)\, n_{1}\end{aligned}[/tex].

The refractive index of air is approximately [tex]1.00[/tex]. Substitute in the values and solve for [tex]n_{2}[/tex], the refractive index of the glass block:

[tex]\begin{aligned}n_{2} &= \left(\frac{\sin(\theta_{1})}{\sin(\theta_{2})}\right)\, n_{1} \\ &= \left(\frac{\sin(46^{\circ})}{\sin(26^{\circ})}\right)\times 1.00 \\ &\approx 1.64\end{aligned}[/tex].

Hi there!

For an object moving in a circle:

Centripetal force = ∑F = mv²/r

Thus:

56 = mv²/r

Rearrange to solve for velocity:

√(56r/m) = v

√(56 × 21)/650 = 1.345 m/s

Answer:

Explanation:

have a good day

Answer:

B

Explanation:

Moment = force * perpendicular distance

Since the beam is balanced(equilibrium), the 2 moments will be equal.

30 * P = 70 * Q

The 2 combinations which achieve this equality is P = 21 and Q = 9

The neutron has no charge, and a mass of slightly over 1 amu. Some scientists propose the neutron is made up of a proton and electron-like particle. The electron is a very small particle located outside the nucleus.

Electron: -1

Neutron: 0

Proton: +1

Answer:

v=30m/s

Explanation:

m = 1500kg

v = 30m/s

t = 25s

The velocity time graph is parallel to the time axis,

that means The Velocity is constant. ('constant' means remains same).

Therefore, after 25s, v=30m/s

Answer: 100 pascals times 0.2 m^2= 20 N force is applied.

Explanation:

The temperature rise in the copper is. I think its 0.393

The temperature rise in the copper is. I think its 0.393. Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29.

The chemical element copper (Cu) is a reddish, incredibly ductile metal belonging to Periodic Group 11 (Ib) that has an exceptional ability to conduct heat and electricity.

In nature, copper can be found in its free metallic state. Neolithic (New Stone Age) humans originally utilised this local copper (about 8000 BCE) as a substitute for stone.

Around 4000 BCE, Mesopotamia saw the beginning of metallurgy as copper was cast into molds, reduced to metal from ores with fire and charcoal, and purposefully alloyed with tin to form bronze (c. 3500 BCE).

Therefore, The temperature rise in the copper is. I think its 0.393. Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29.

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Answer:

Less than one percent of the total energy that reaches Earth is used by plants for photosynthesis

The conservation of the momentum allows to find the velocity of the second body after the elastic collision is:

           [tex]v_f = \frac{2u_o}{1- \frac{m_2}{m_1} }[/tex]  

the momentum is defined by the product of the mass and the velocity of the body.

        p = mv

The bold letters indicate vectors, p is the moment, m the mass and v the velocity of the body.

If the system is isolated, the forces during the collision are internal and the it  is conserved. Let's find the momentum is two instants.

Initial instant. Before crash.

      p₀ = m₁ u₀ + 0

Final moment. After crash.

      [tex]p_f = m_1 u_f + m_2 v_f[/tex]  

The momentum is preserved.

      p₀ = [tex]p_f[/tex]  

      [tex]m_1 u_o = m_1 u_f + m_2 v_f[/tex]  

Since the collision is elastic, the kinetic energy is conserved.

      K₀ = [tex]K_f[/tex]

      ½ m₁ u₀² = ½ m₁ [tex]u_f^2[/tex]  + ½ m₂  [tex]v_f^2[/tex]  

Let's write our system of equations.

       [tex]m_1 u_o = m_1 u_f + m_2 v_f \\m_1 u_o^2 = m_1 u_f^2 + m_2 v_f^2[/tex]

Let's solve

       [tex]u_f = u_o - \frac{m_2}{m_2} \ v_f \\u_f^2 = u_o^2 - \frac{m_2}{m_1} \ v_f^2[/tex]

       [tex]( u_o - \frac{m_2}{m_1} v_f)^2 = u_o - \frac{m_2}{m_1} \ v_f^2 \\u_o^2 - 2 \frac{m_2}{m_1} \ u_o v_f + (\frac{m_2}{m_1} )^2 v_f^2 = u_o^2 - \frac{m_2 }{m_1} \ v_f^2[/tex]  

        [tex]2 \frac{m_2}{m_1} \ u_o = \frac{m_2}{m_1} v_f \ ( 1 - \frac{m_2}{m_1}) \\v_f = \frac{2u_o}{1-\frac{m_2}{m_1} }[/tex]

In conclusion, using the conservation of momentum, we can find the velocity of the second body after the elastic collision is:

           [tex]v_f = \frac{2u_o}{1-\frac{m_2}{m_1} }[/tex]  

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What is the weight of a car with the mass of 1000 kg?

Answer: it is 9800 N.

Answer:

10

Explanation:

if you put 10 your right

Answer:

not sure, but I thinks it's either Transparent or Reflective

According to the concept of reflection, if  a piece of glass permits light to pass through, then it is considered to be reflective.

Reflection of light is defined as a property of light ray that when it strikes a smooth surface it bounces back .Objects can be seen due to this property of light.Reflection is produced by all types of waves namely sound waves, light waves, electromagnetic waves.

Reflection of light is governed by laws of reflection which are also called as Snell's laws. According to laws of reflection, angle of incidence and angle of reflection are equal.The incident ray , reflected ray and normal all lie on the same side of the plane.Light travels in a straight line before, after and during the process of reflection.There are 3 types of reflection which are diffuse reflection,specular reflection and glossy reflection.

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The amount of work done to stop the car is equal to 322,099.85 Joules.

Given the following data:

Conversion:

Velocity = 95 km/h = [tex]\frac{95 \times 1000}{60 \times 60} = 26.39 \;m/s^2[/tex]

To determine the amount of work done to stop the car, we would apply the work-energy theorem:

Note: The amount of work done must balance the kinetic energy possessed by the car due to its motion.

From the work-energy theorem, we have:

[tex]Work\done = \Delta K.E\\\\Work\done = \frac{1}{2} MV^2[/tex]

Substituting the given parameters into the formula, we have;

[tex]Work\;done = \frac{1}{2} \times 925 \times (26.39)^2\\\\Work\;done =462.5 \times 696.4321[/tex]

Work done = 322,099.85 Joules

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Answer:

Electromagnetic waves are waves that have no medium to travel whereas mechanical waves need a medium for its transmission. Electromagnetic waves travel in a vacuum whereas mechanical waves do not. The mechanical waves need a medium like water, air, or anything for it to travel.

Explanation:

Answer:

They will go backwards?

Explanation:

If positive they go forward but is negative they go backwards.

Answer:

Census includes the total process of collecting, compiling, analyzing, evaluating, publishing and disseminating statistical data regarding the population and housing and their geographical location. Population characteristics include demographic, social and economic data and are provided as of a particular date (reference period).

Census Methods:

Population censuses typically use one of two approaches:

De facto – meaning enumeration of individuals as of where they are found in the census, regardless of where they normally reside.

De jure - meaning enumeration of individuals as of where they usually reside, regardless of where they are on census day.

Answer:

No

Explanation:

The rate of diffusion defines the gas that passes through some area over the course of time.

Answer:

(D)

E = V Q      energy of charge Q  thus V = E / Q

[tex] \: \: \: \: \: [/tex]

hope it helps

[tex] \: \: \: \: \: [/tex]

Answer:

2 m/s2

Explanation:

the answer is 2 m/s2