A 2-kilogram toy car is traveling forward at 1 meter per second when it is hit in the rear by a 3-kilogram toy truck that was traveling at 3 meters per second just before impact. If the two toys stick together, their speed immediately after the collision is

Answer:

a) [tex]\Delta S_{in} = 2.791\,\frac{J}{K}[/tex], b) [tex]\Delta S_{out} = 6.897\,\frac{J}{K}[/tex], c) [tex]S_{gen} = 4.106\,\frac{J}{K}[/tex], d) Due to irreversibilities due to temperature differences.

Explanation:

a) The change in entropy of the hot reservoir is:

[tex]\Delta S_{in} = \frac{2400\,J}{860\,K}[/tex]

[tex]\Delta S_{in} = 2.791\,\frac{J}{K}[/tex]

b) The change in entropy of the cold reservoir is:

[tex]\Delta S_{out} = \frac{2400\,J}{348\,K}[/tex]

[tex]\Delta S_{out} = 6.897\,\frac{J}{K}[/tex]

c) The total change in entropy of the Universe is modelled after the Second Law of Thermodynamics. Let assume that process is steady:

[tex]\Delta S_{in} - \Delta S_{out} + S_{gen} = 0[/tex]

[tex]S_{gen} = \Delta S_{out} - \Delta S_{in}[/tex]

[tex]S_{gen} = 6.897\,\frac{J}{K} - 2.791\,\frac{J}{K}[/tex]

[tex]S_{gen} = 4.106\,\frac{J}{K}[/tex]

d) Since irreversibilities create entropy as process goes by. The main source of irreversibilities is the existence of temperature differences.

Answer: A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding. Often, physical changes can be undone, if energy is input.

Explanation: hope this helps have a good day

Answer:

If the reaction is a chemical change, new substances with different properties and identities are formed. This may be indicated by the production of an odor, a change in color or energy, or the formation of a solid.

Answer:

  8.3 feet

Explanation:

The kinetic energy of the system on the ground is ...

  KE = Σ(1/2)(mv^2) = (1/2)(155)(24^2) +(1/2)(13)(0^2) = 44640 lb·ft²/s²

The potential energy at the highest point is the same:

  PE = mgh

  44640 = (155 +13)(32)h

  h = 44640/5376 = 8.30 . . . . feet

_____

We haven't worried too much about the conversion between pounds mass and pounds force. Whatever factor may be involved will divide out when computing the maximum height. We have used g=32 ft/s².

__

To achieve a 10 ft height, the running speed would need to be 26.34 ft/s, about 10% higher.

Answer:

EACH SEX CELL WILL HAVE 10 CHROMOSOMES BECAUSE n+n=2n

means haploid parent cells join or fuse to form diploid zygote

Answer:

10

Explanation:

Answer:

Coefficient of kinetic friction = 0.146

Explanation:

Given:

Mass of sled (m) = 18 kg

Horizontal force (F) = 30 N

FInal speed (v) = 2 m/s

Distance (s) = 8.5 m

Find:

Coefficient of kinetic friction.

Computation:

Initial speed (u) = 0 m/s

v² - u² = 2as

2(8.5)a = 2² - 0²

a = 0.2352 m/s²

Nweton's law of :

F (net) = ma

30N - μf = 18 (0.2352)

30 - 4.2336 = μ(mg)

25.7664 =  μ(18)(9.8)

μ = 0.146

Coefficient of kinetic friction = 0.146

Answer: A and D

a. Many objects move in arcs of circles or complete circles at times, and polar coordinates allowthe motion of such objects to be comprehended more easily. Some of Newton's laws in certaincases, such as calculation ofg from first principles, are much easier to calculate using polar coordinates.

b. "These coordinates are just used to confuse students.

c. ""Physics teachers are helping math teachers by getting students to practice theirtrigonometry.

d. ""In some cases, such as addition of forces, where a force magnitude is specified, it is simpler todescribe the forces in polar coordinates and be able to convert to the xy representation.

Explanation:

(A). Any force possessing a fixed magnitude and direction, it's always important to describe the for exactly as it is and also be able to convert it from one coordinate representation to another.

(D). Anything which involves radial motion(this is a motion along a radius) or motion along an arc of a circle or ellipse, this kind of motion is best explained and easily understood when in polar coordinates.

Answer:

1. 25 Km

2. zero

3. 27.7 m/s

Explanation:

Data provided in the question:

Circumference of the track = 12.5 km

Speed of the car = 100 Km/h

Time for which car travels = 15 minutes = [tex]\frac {15}{60}[/tex] hr

Now,

1. Distance traveled = Speed × Time

= 100 × [tex]\frac{15}{60}[/tex]

= 25 Km

2. The distance traveled is 2 times the circumference of the track (i.e 2 × 12.5 = 25 Km)

Which means that the car is again at the initial position

Therefore, The displacement is zero.

3. Speed of car in Km/hr = 100 Km/h

now,

1 Km = 1000 m

1 hr = 3600 seconds

therefore,

100 Km/h = [tex]100\times\frac{1000}{3600}[/tex] m/s

= 27.7 m/s

Hence, the speed of car in m/s = 27.7

Answer:

Explanation:

 Time taken by sound waves to cover distance between politician and reporter = time taken by em waves to travel distance between politician and the television viewer.

5.5 / 343 = d / 3 x 10⁸ + 2.7 / 343

d is distance between politician and television set + time taken by sound to travel distance between television and its viewer.

.0160349 = d / 3 x 10⁸  + .0078717

d / 3 x 10⁸  = .0081632

d = 2448960 m

= 2448.96 km

= 2449 km .

Answer:

The drag (air resistance) it experiences along its flight to the basket, due to the shape and surface area of the socks, the size of the sock (weight), and the speed with which the socks is tossed.

Explanation:

The socks, like every other particle or body travelling through air is met by a resistance that impedes its motion. This resistance is due to the air molecules around, that collide with the body as it travels through them. The resistance offered by this force is proportional to the surface area of the body that collides with the air molecule, so, rolling the socks into a ball reduces the effect of air resistance on the socks, compared to the one tossed without rolling. Air resistance is also largely dependent on the relative motion of the body and the air molecules, the density of the fluid (air), and the size of the body (weight).

Therefore, whether the socks lands in the basket or not is affected by the drag (air resistance) it experiences along its flight to the basket, due to the shape and surface area of the socks, size of the socks (weight), and the speed with which the socks is tossed.

Drag force opposes motion of objects through fluid with its magnitude depending on the velocity of the object in the fluid

The single parameter that effects whether or not the socks lands in the basket is the drag force, [tex]\mathbf{F_D}[/tex] acting on the socks

[tex]F_D = \mathbf{C_D \times A \times \dfrac{\rho \times v_r^2}{2}}[/tex]

The reason that drag force is the parameter that effects the landing point of the socks is as follows:

The parameters that effects whether or not the socks land in the basket or not are;

The parameters, R, u, and θ depends on the thrower, that parameter that effects the whether or not the socks lands in the basket that is independent of the thrower, is the drag, [tex]\mathbf{F_D}[/tex]

Drag is the force opposing (slows) the motion of an object in a fluid.

The drag force, [tex]\mathbf{F_D}[/tex], slowing down motion, is given by the following formula;

[tex]F_D = \mathbf{C_D \times A \times \dfrac{\rho \times v_r^2}{2}}[/tex]

Where;

[tex]v_r[/tex] = The velocity of flow of the fluid, relative to the object

ρ = The density of the fluid

[tex]C_D[/tex] = The drag coefficient

A = The cross sectional area of the fluid

Therefore, the independent parameter that effects whether or not the socks lands in the basket is the drag force on the socks

Learn more about drag force here:

https://brainly.com/question/17074446

Answer:

The length of organ pipe A is [tex]L = 0.3611 \ m[/tex]

The length of organ pipe B is  [tex]L_b = 0.2708 \ m[/tex]

Explanation:

From the question we are told that

    The fundamental frequency is  [tex]f = 475 Hz[/tex]

     The speed of sound is  [tex]v_s = 343 \ m/s[/tex]

The fundamental frequency of the organ pipe A  is mathematically represented as

        [tex]f= \frac{v_s}{2 L}[/tex]

Where L is the length of  organ pipe

   Now  making L the subject

        [tex]L = \frac{v_s}{2f}[/tex]

substituting values

        [tex]L = \frac{343}{2 *475}[/tex]

        [tex]L = 0.3611 \ m[/tex]

The second harmonic frequency of the  organ pipe A is mathematically represented as

       [tex]f_2 = \frac{v_2}{L}[/tex]

The third harmonic frequency of the  organ pipe B is mathematically represented as      

      [tex]f_3 = \frac{3 v_s}{4 L_b }[/tex]

So from the question

       [tex]f_2 = f_3[/tex]

So

    [tex]\frac{v_2}{L} = \frac{3 v_s}{4 L_b }[/tex]

Making  [tex]L_b[/tex] the subject

     [tex]L_b = \frac{3}{4} L[/tex]

substituting values

    [tex]L_b = \frac{3}{4} (0.3611)[/tex]

    [tex]L_b = 0.2708 \ m[/tex]

B and D are both true statements. I'm not comfortable saying that either one is better than the other one.

The statement that best describes one way that molecules differ from atoms is a molecule can contain two atoms of the same element, and only a molecule can be broken down into two or more different elements. The correct options are b and d.

According to science, an atom is the smallest component of an element that can exist freely or not. A molecule, on the other hand, is the smallest component of a chemical and is made up of a group of atoms linked together by a bond.

A molecule is the smallest component of a substance that has the chemical properties of the compound.

The term "independent molecule" is not commonly used to refer to atoms and complexes linked by non-covalent interactions such as hydrogen or ionic bonds. Molecules are common constituents of matter.

Therefore, the correct options are b and d.

To learn more about atoms, refer to the link:

https://brainly.com/question/25617532

#SPJ2

Answer:

the statements the B is not true

Explanation:

In the stars the force of gravity tends to collapse them, by joining the atoms nuclear reactions that create an outward force until the two forces reach an equilibrium

The temperature of a star is a reflection of the energy within it and it is related to the intensity of the nuclear rations and not to the size of the stars

In examining the statements the B is not true

Answer:

C

Explanation:

Because everything on Earth falls at the same speed, the masses of the balls do not matter. Since the acceleration due to gravity is constant, their speeds will both be increasing at the same rate, and therefore the difference in speeds would remain constant until they hit the ground. Hope this helps!

Answer:

3.2 m/s

Explanation:

Given:

Δx = 1000 m

v₀ = 23 m/s

a = -0.26 m/s²

t = 76 s

Find: v

This problem is over-defined.  We only need 3 pieces of information, and we're given 4.  There are several equations we can use.  For example:

v = at + v₀

v = (-0.26 m/s²) (76 s) + (23 m/s)

v = 3.2 m/s

Or:

Δx = ½ (v + v₀) t

(1000 m) = ½ (v + 23 m/s) (76 s)

v = 3.3 m/s

Or:

v² = v₀² + 2aΔx

v² = (23 m/s)² + 2(-0.26 m/s²)(1000 m)

v = 3.0 m/s

Or:

Δx = vt − ½ at²

(1000 m) = v (76 s) − ½ (-0.26 m/s²) (76 s)²

v = 3.3 m/s

As you can see, you get slightly different answers depending on which variables you use.  Since 1000 m has 1 significant figure, compared to the other variables which have 2 significant figures, I recommend using the first equation.

Answer:

Plutonium–238

Explanation:

The stability of isotopes is largely dependent on their half-life.

Half life of an isotope is the time taken for the initial mass of the isotope to be halfed or we can say that the half-life of an isotope is the time taken for the mass of the isotope to become half the initial mass.

From the above definition, we discovered that if the time taken for the mass of the isotope to become half its initial mass is long, then the isotope must be very stable. On the other hand, if the time taken to become half its initial mass is short, then the isotope is unstable because.

We can thus say that, the longer the half-life the more stable the isotope and the shorter the half-life, the less stable the isotope will be.

Considering the table given in the question above and with the ideas we have obtained from the explanation above, we can see that Plutonium–238 has the longest half-life. Therefore Plutonium–238 will be more stable.

' A ' looks like the best choice.

Answer:

B.  inverse plot, 0.51 kilograms/meter3

Explanation:

Answer:

6,650 newtons

Explanation:

The computation of the force exerted on it by static friction is shown below:

Data provided in the question

Mass of car = m = 1,900 kg

speed = v = 14 m/s

radius = r = 56 m

Let us assume friction force be f

And, the Coefficient of friction = [tex]\mu[/tex]= 0.88

As we know that

[tex]f = \frac{mv^2}{r}[/tex]

[tex]= \frac{1,900 \times 14^2}{56}[/tex]

= 6,650 newtons

We simply applied the above formula so that the force exerted could come

Answer:

19.872 degrees

Explanation:

Mathematically;

Using Snell’s law

n1 sin A = n2 sinB

Where ;

n1 = refractive index in air = 1

n2 is refractive index in water = 1.33

A = ?

B = 45

Substituting the values in the equation;

1 sin A = 1.33 sin45

Sin A = 1.33 sin 45

A = arc sin (1.33 sin 45)

A = 70.12

Thus, the actual direction of the Sun with respect to the horizon = 90-A = 19.872 degrees

Note: The complete question is attached as a file to this solution. The parallel plate mentioned can be seen in this picture attached.

Answer:

E = 225 N/C

Explanation:

Note: At any point on the parallel plates of a capacitor, the electric field is uniform and equal.

Therefore, Electric field at x = 14 cm equals the electric field at x = 7 cm

V(x) = 31.5 Volts

x = 14 cm = 0.14 m

The magnitude of the electric field at any point between the parallel plate of the capacitor is given by the equation:

E = V(x)/d

E(x = 0.14) = 31.5/0.14

E(x=0.14) = 225 N/C

E(x=0.14) = E(x=0.07) = 225 N/C

Answer:

Explanation:

The Law of Energy Conservation states that K1 + U1 = K2 + U2

m= 72.0 kg

h= 3.90 m

a)

K1 + U1 = K2 + U2

0 + mgh = 1/2mvf^2 + 0

mass cancels out so gh=1/2vf^2

(9.8 m/s^2)(3.9 m)=(.5)(vf^2)

vf= 8.74 m/s

b)

1/2mv^2 + mgh = 1/2mv^2 + 0

mass cancels again

(.5)(2.9^2 m/s) + (9.8 m/s^2)(3.9 m) = (.5)(vf^2)

vf= 9.21 m/s

c)

This would be the same as the past problem as the velocity gets squared so direction along the axis doesn't matter. Thus, vf= 9.21 m/s

Answer:

Explanation:

The man comes to halt due to reaction force acting on him in opposite direction . If R be the reaction force

impulse by net  force = change in momentum

Net force = R - mg , mg is weight of the man .

( R-mg ) x 2. 07 x 10⁻³ = 73 x 6.46 - 0

R - mg = 227.81 x 10³

Average net force = 227.81 x 10³ N .

Explanation:

We have, a pendulum on a planet, oscillates with a time period 5 sec. The formula used to find the time period is given by :

[tex]T=2\pi \sqrt{\dfrac{l}{g}}[/tex]

l is length of the pendulum

g is acceleration due to gravity on which it is placed

It is clear that, the time period of pendulum is independent of the mass. Hence, if the mass is increased six times, its time period remains the same.

Answer:

12.0 V

Explanation:

Data :

Potential difference due to a single charge (+Q), E = 3.0 V

The Electric potential for the system of charges is given as:

[tex]E=\frac{1}{4\pi \epsilon_o}[\Sigma\frac{Q}{r}][/tex]

for single charge, E = 3.0 V = [tex]\frac{1}{4\pi \epsilon_o}[\frac{Q}{r}][/tex]  ->eq(1)

And for 4 charges:

[tex]E=\frac{1}{4\pi \epsilon_o}[4\frac{Q}{r}][/tex] -eq(2)

from eq(1) and (2) we have

E = 4 × 3.0 V = 12 V

Answer:

32N

Explanation:

The Left force exerts an opposite horizontal force of 32N on the middle object

Answer:

a. 0.16240664737515434 moles

b. 67.5 degrees Celcius

Explanation:

a. Use Ideal Gas Equation

PV=nRT

Where P = pressure in pascals, V=Volume in cubic meters, n=number of moles, R is a constant=8.314 J/mol.K and T is temperature in Kelvin.

27C = 273+27=300Kelvin

volume 4L = 0.004m^3

Pressure = 1atm = 101325 Pascal

PV=nRT

101325Pa*0.004m^3=n*8.314J/mol.K*300K

Solving for n from the above you get n=0.16240664737515434 moles

b.Use combined gas law equation

P1*V1/T1=P2*V2/T2

P1= 1atm

V1=4L

T1=27C

P2= 4/16 L =0.25L

P=1*40 atm = 40atm

We do not know T2

USING THE FORMULA

(1atm*4L)/27C = (40atm*0.25L)/T2

(1*4)/27=(40*0.25)/T2

IF you simplify for T2, you get 67.5

Hence final temperature = 67.5 degrees Celcius

Answer:

D

Explanation:

Insoluble impurities would not change the constituent of the substance. Soluble would for example salt water takes longer time for the water to become vapour when subjected to the same temperature that normal water.

Wind would affect, the more windy the tendency for particles of the liquid to be moved into the atmosphere.

With an increase in surface area, the evaporation rate increase . Take a clue from water placed on the ground and exposed to the atmosphere and that same quantity of water is placed in a cup. That on the floor would evaporate faster.

Similarly the higher the temperature a substance is subjected to the easier is it's rate of evaporation. Take for instance water in a cup placed in the sun and that same placed in a room with mild temperatures than that of the sun.With time that in the sun decreases in volume faster than that in the room.

Complete question is;

Assuming 100% efficient energy conversion how much water stored behind a 50 centimeter high hydroelectric dam would be required to charge the battery with power rating, 12 V, 50 Ampere-minutes

Answer:

Amount of water required to charge the battery = 7.35 m³

Explanation:

The formula for Potential energy of the water at that height = mgh

Where;

m = mass of the water

g = acceleration due to gravity = 9.8 m/s²

H = height of water = 50 cm = 0.5 m

We know that in density, m = ρV

Where;

ρ = density of water = 1000 kg/m³

V = volume of water

So, potential energy is now given as;

Potential energy = ρVgH = 1000 × V × 9.8 × 0.5 = (4900V) J

Now, formula for energy of the battery is given as;

E = qV

We are given;

q = 50 A.min = 50 × 60 = 3,000 C

V = 12 V

Thus;

qV = 3,000 × 12 = 36,000 J

E = 36,000 J

At a 100% conversion rate, the energy of the water totally powers the battery.

Thus;

(4900V) = (36,000)

4900V = 36,000

V = 36,000/4900

V = 7.35 m³

Answer:

The electric flux is  [tex]\phi = 2.5 *10^{3} \ Nm^2 \cdot C^{-1}[/tex]

Explanation:

From the question we are told that

  The magnitude of the electric point charge  [tex]q = 22.5 nC = 22.5 *10^{-9} \ C[/tex]

   The length of the one side of the cube is [tex]l = 16.3 \ cm = 0.163 \ m[/tex]

   The number of  sides is  [tex]N= 6[/tex]  

The electric flux according to Gauss law is mathematically evaluated as

          [tex]\phi = \frac{q}{\epsilon_o}[/tex]

Where [tex]\epsilon _ o[/tex] is the permitivity of free space with value  [tex]\epsilon_o = 8.85*10^{-12}\ m^{-3} \cdot kg^{-1}\cdot s^4 \cdot A^2[/tex]

  substituting values

        [tex]\phi = \frac{22.5 *10^{-9}}{8.85 *10^{-12}}[/tex]

         [tex]\phi = 2.5 *10^{3} \ Nm^2 \cdot C^{-1}[/tex]

Answer:

13.9 kJ

Explanation:

Given that

Length of the side, l = 1.8 m

Drag coefficient, C(d) = 1.4

Distance of run, d = 200 m

Velocity of run, v = 5 m/s

Density, ρ = 1.23

Using the Aerodynamics Drag Force formula. We have

F(d) = 1/2.ρ.A.C(d).v²

The Area, A needed is 1.8 * 1.8 = 3.24 m². So that,

F(d) = 1/2 * 1.23 * 3.24 * 1.4 * 5²

F(d) = 139.482/2

F(d) = 69.74

recall that, energy =

W = F * d

W = 69.74 * 200

W= 13948

W = 13.9kJ

Therefore, the thermal energy added to the air by the drag force is 13.9kJ

Answer:

Explanation:

Initial kinetic energy of the system = 1/2 mA v0²

If Vf be the final velocity of both the carts

applying conservation of momentum

final velocity

Vf = mAvo / ( mA +mB)

kinetic energy ( final ) =  1/2 (mA +mB)mA²vo² /  ( mA +mB)²

= mA²vo²  / 2( mA +mB)

Given 1/2 mA v0²  / mA²vo²  / 2( mA +mB) = 6

mA v0² x ( mA +mB) / mA²vo² = 6

( mA +mB) / mA = 6

mA + mB = 6 mA

5 mA = mB

mB / mA = 5 .