2. Sadie is experimenting with a model steam engine. Before the 0.25kg of water begins to boil it needs to be heated from 20°C to 100°C. If the specific heat capacity of water is 4180J/kg°C, how much thermal energy is needed to get the water up to boiling point?​

Answer:

[tex](75.0 \times 30) + (60.0 \times 6.0) = (75.0 \times V) + (60.0 \times 0) \\ 2250 + 360 = 75V \\ 75V = 2610 \\ V = 34.8 \: m {s}^{ - 1} [/tex]

Answer:

144 meters

Explanation:

the ball is thrown with a speed of 24 meters per second right so if the ball reaches the ground in 6 seconds. the hight of the cliff must be S=v.t

S (height cliff)=24m/s×6s=144

The question is incomplete, the complete question is;

In addition to absorption of a photon, energy can be transferred to an atom by collision. Consider a hydrogen atom in its ground state. Incident on the atom are electrons having a kinetic energies of 10.5 eV. What is a possible result?

A) The atom moves to a state of lower energy

B) The atom is ionized

C) One of the electrons leaves the atom

D) The atom can be excited to a higher energy state

Answer:

The atom can be excited to a higher energy state

Explanation:

According to the Bohr model of the atom, electrons in an atom can be excited from a lower to a higher energy level when energy is absorbed by the atom.

If electrons having an energy of 10.5ev are incident on a hydrogen atom, this energy is transferred to the atom by collision. Since the energy transferred is less than the ionization energy of hydrogen atom in its ground state(13.6ev), the atom is not ionized.

Rather, the atom is excited from ground state to a higher energy level.

A resistor in an electrical circuit opposes the flow of electrons by providing resistance to the current. The correct option is C

A resistor is a passive electrical device that controls or restricts how much electrical current can flow across a circuit in an electronic device.

High electrical resistance materials, such carbon, metal film, or wirewound, are used to make resistors. Ohms (Ω) are used to measure a resistor's resistance. A resistor's resistance determines how much it will fight against the flow of electrical electricity.

Therefore, A resistor's resistance is the degree of opposition it offers. The more resistance present, the more challenging it is for electrons to move across the circuit.

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Answer:

A

Explanation:

If the object is moving at a constant speed, the object isn't accelerating as the velocity doesn't change.

Answer: C.

Explanation:  plato users

Answer:

   x_total = 3.07 m

Explanation:

Let's analyze the situation presented, in this case we have the data to find the angle of incidence and with the law of refraction we can find the angle of refraction.

Let's start looking for the angle with which the laser pointer reaches the water, let's use trigonometry

          tan θ₁ = 1.0 /2.0

          θ₁ = tan⁻¹ 0.50

          θ₁ = 26.57º

now let's use the law of refraction to find the angle of refraction (in water)

          n₁ sin θ₁ = n₂ sin θ₂

the refractive index of air is n₁ = 1 and that of water n₂ = 1.33

         sin θ₂ = [tex]\frac{n_1}{n_2} \ sin \theta_1[/tex]

         sin θ₂ = [tex]\frac{1}{1.33} \ sin \ 26.57[/tex]

         θ₂ = sin⁻¹ 0.3363

         θ₂ = 19.65º

now we can find the distance from the entry point to the water to the lenses

         tan θ₂ = x₂ / 3

         x₂ = 3 tan θ₂

         x₂ = 3 tan 19.65

         x₂ = 1.07 m

the total distance from the edge of the pool is

        x_total = 2 + x₂

        x_total = 2 + 1.07

        x_total = 3.07 m

Answer:

0.53 quart

Explanation:

The volume expansion of the coolant is gotten from ΔV = VγΔθ where ΔV   = change in volume of the coolant, V = initial volume of coolant = 15 quart, γ = coefficient of volume expansion of coolant = 410 × 10⁻⁶ /°C and Δθ = temperature change = θ₂ - θ₁ where θ₁ = initial temperature of coolant = 6 °C and θ₂ = final temperature of coolant = 92 °C. So, Δθ = θ₂ - θ₁ = 92 °C - 6 °C = 86 °C

Since, ΔV = VγΔθ

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

ΔV = VγΔθ

ΔV = 15 × 410 × 10⁻⁶ /°C × 86 °C

ΔV = 528900 × 10⁻⁶ quart

ΔV = 0.528900 quart

ΔV ≅ 0.53 quart

Since the change in volume of the coolant equals the spill over volume, thus the overflow from the radiator will spill into the reservoir when the coolant reaches its operating temperature of 92 °C is 0.53 quart.

Answer:

Mechanical energy

Explanation:

If an object does not have any momentum, then it doesn't have mechicanl energy.

Answer:

O Distant objects are blurry. describes farsightedness.

Explanation:

Farsightedness (hyperopia) is a common vision condition in which you can see distant objects clearly, but objects nearby may be blurry. The degree of your farsightedness influences your focusing ability.Farsightedness (hyperopia) is a common vision condition in which you can see distant objects clearly, but objects nearby may be blurry.

Answer:

d) and e)

Explanation:

Answer: When it comes to the movement of air, friction is greater near the ground surface.

Explanation:

A resistance in motion observed by an object while on another object is called friction.

For example, a vehicle moving on road will have friction between its tires and the road.

Friction is more near the ground surface rather than away from the ground surface.

Thus, we can conclude that when it comes to the movement of air, friction is greater near the ground surface.

Answer:

D. Non- polar solvant

Explanation:

l think that's it

Answer:

I think the answer is D polar solvent

Answer:

C. ...

D. ...

Given.

Required.

Solution.

As the temperature decreases, the equilibrium will shift towards the exothermic reaction, so the reaction shifts to the right towards SO₃( products-favored)

And increasing the pressure, then the reaction shifts to the right SO₃( products-favored)⇒the number of coefficients is greater.

Answer:

decrease the temperature

and

raising the pressure

Explanation:

Answer:

wait

Explanation:

Answer:

Tenemos dos problemas a resolver acá:

Primero, debemos encontrar la velocidad con la que la pelota impacta el suelo.

Acá podemos usar la conservación de la energía.

E = U + K

U = energía potencial = m*g*H

m = masa

g = aceleración gravitatoria = 9.8m/s^2

H = altura

K = energía cinética = (m/2)*V^2

donde V es la velocidad.

Inicialmente, cuando la pelota es soltada, su velocidad es cero, entonces solo tenemos energía potencial:

Ei = U = m*(9.8m/s^2)*2.5m

Al final, cuando la pelota esta por impactar el suelo, la altura tiende a cero, entonces ya no hay energía potencial, solo hay energía cinética:

Ef = (m/2)*V^2

Y como la energía se conserva, la energía final es igual a la inicial, entonces:

m*(9.8m/s^2)*2.5m = (m/2)*V^2

Podemos resolver esto para V, y asi obtener la velocidad con la que la pelota impacta el suelo.

V = √(2*(9.8m/s^2)*2.5m) = 7m/s

Ahora respondamos la segunda parte.

Una vez la pelota rebota, su aceleración va a estar dada solamente por la aceleración gravitatoria, entonces tenemos:

A(t) = -9.8m/s^2

Para obtener su velocidad integramos:

V(t) = (-9.8m/s^2)*t + V0

donde V0 es la velocidad con la que la pelota reboto, que sabemos que es 3/4 de 7m/s

V0 = (3/4)*7m/s = (21/4) m/s

Así, la ecuación de la velocidad es:

V(t) = (-9.8m/s^2)*t + (21/4) m/s

Sabemos que la altura máxima se da cuando la velocidad es igual a cero, entonces primero calculemos el valor de t tal que esto ocurra:

V(t) = 0 = (-9.8m/s^2)*t + (21/4) m/s

         t =  (21/4) m/s/9.8m/s^2 = 0.54 s

Ahora debemos encontrar la ecuación de la posición y evaluarlo en este tiempo.

Para ello integramos de vuelta:

P(t) = (1/2)(-9.8m/s^2)*t^2 + (21/4 m/s)*t + P0

donde P0 es la posición inicial, como la pelota rebota en el suelo, la posición inicial es el suelo, el cual representamos con 0, entonces la ecuación de la posición es:

P(t) = (1/2)(-9.8m/s^2)*t^2 + (21/4 m/s)*t  

La altura máxima estará dada por esta ecuación evaluada en t = 0.54 s

P(0.54s) =  (1/2)(-9.8m/s^2)*(0.54s)^2 + (21/4 m/s)*0.54s = 1.81 m

La altura máxima es 1.81 metros.

Y entre que rebota y llega a esta altura máxima, transcurren 0.54 segundos.

Answer:

16.9000000000000001 J

Explanation:

From the given information:

Let the initial kinetic energy from point A be [tex]K_A[/tex] = 1.9000000000000001 J

and the final kinetic energy from point B be [tex]K_B[/tex] = ???

The charge particle Q = 6 mC = 6 × 10⁻³ C

The change in the electric potential from point B to A;

i.e. V_B - V_A = -2.5 × 10³ V

According to the work-energy theorem:

-Q × ΔV = ΔK

[tex]-Q \times ( V_B - V_A) = (K_B - K_A)[/tex]

[tex]-(6\times 10^{-3}\ C) \times ( -2.5 \times 10^3) = (K_B - 1.9000000000000001 \ J)[/tex]

[tex]15 = (K_B - 1.9000000000000001 \ J)[/tex]

[tex]K_B = 15+ 1.9000000000000001 \ J[/tex]

[tex]\mathbf{K_B =1 6.9000000000000001 \ J}[/tex]

Answer:

parallel circuit

Explanation:

An electric circuit can be defined as an interconnection of electrical components which creates a path for the flow of electric charge (electrons) due to a driving voltage.

Generally, an electric circuit consists of electrical components such as resistors, capacitors, battery, transistors, switches, inductors, etc.

Basically, the components of an electric circuit can be connected or arranged in two forms and these includes;

I. Series circuit

II. Parallel circuit: it's an electrical circuit that has the same potential difference (voltage) across its terminals or ends. Thus, its components are connected within the same common points so that only a portion of current flows through each branch.

Hence, the type of circuit that the above diagram above represents is a parallel circuit.

Answer:

parallel circuit

Explanation:

I got it right on my exam

Answer:

The inductance of the solenoid is 71.98 mH

Explanation:

Given;

number of loops per length of the solenoid, n = 100 loops/cm

radius of the solenoid, r = 4.53 cm

length of the solenoid, L = 8.88 cm

current carried by the solenoid, I = 500 mA

The inductance of the solenoid is calculated as;

[tex]L = \frac{N^2\times \mu_0 \times A}{l}[/tex]

where;

A is the area of the coil

[tex]A =\pi r^2 = \pi (0.0453)2 = 0.00645 \ m^2[/tex]

N is the number of turns, = 100 x 8.88 = 888 loops

l is the length = 0.0888 m

[tex]L = \frac{N^2\times \mu_0 \times A}{l}\\\\L = \frac{(888)^2\times \(4\pi \times 10^{-7}) \times (0.00645)}{0.0888}\\\\L = 0.07198 \ H\\\\L = 71.98 \ mH[/tex]

Therefore, the inductance of the solenoid is 71.98 mH

Answer:

As it is the most efficient heat engine, it's efficiency is [T1 - T2]/T1. It can be measured for every Carnot cycle. From the formula and diagram, we can understand that the efficiency of an ideal heat engine also depends on the difference between the hot and cold reservoirs.

Explanation:

Answer:

165.8 V/m

Explanation:

The capacitance of a long concentric cylindrical shell of length, L and inner radius, a and outer radius, b is C = 2πε₀L/㏑(b/a)

Since the charge on the cylindrical shells, Q = CV where V = the potential difference across the capacitor(which is the potential difference between the concentric cylindrical shells)

V = Q/C

V = Q ÷ 2πε₀L/㏑(b/a)

V = Q㏑(b/a)/2πε₀L

So, the potential difference per unit length V' is

V' = V/L = Q㏑(b/a)/2πε₀

Given that a = inner radius = 1.5 cm, b = outer radius = 5.6 cm and Q = 7.0 nC = 7.0 × 10⁻⁹ C and ε₀ = 8.854 × 10⁻¹² F/m substituting the values of the variables into the equation, we have

V' = Q㏑(b/a)/2πε₀

V' = 7.0 × 10⁻⁹ C㏑(5.6 cm/1.5 cm)/(2π × 8.854 × 10⁻¹² F/m)

V' = 7.0 × 10⁻⁹ C㏑(3.733)/(55.631 × 10⁻¹² F/m)

V' = 7.0 × 10⁻⁹ C × 1.3173/(55.631 × 10⁻¹² F/m)

V' = 9.2211 × 10⁻⁹ C/(55.631 × 10⁻¹² F/m)

V' = 0.16575 × 10³ V/m

V' = 165.75 V/m

V' ≅ 165.8 V/m

Answer:

  a₃ = -1.08 m/s²,    K = 1.42 J

Explanation:

The particle is in a periodic motion, so the general expression is

           x = A cos (wt + Ф)

let's compare the terms with the expression they give us

           x = 2 cos (t - 2)

the amplitude of motion is A = 2 m, the angular velocity w = 1 rad / s, and the phase is Ф = - 2.

to find the acceleration we use its definition

          v = dx / dt

          a = dv / dt

          a = [tex]\frac{ d^2x}{dt^2}[/tex]

let's perform the derivative

          v = - A w sin (wt + Ф)

          a = - A w² cos wt + Ф)

substituting the values

          a = - 2 1² cos (t-2)

for t = 3 s

          a₃ = 2 cos (3-2)

remember angles are in radians

          a₃ = -1.08 m/s²

To calculate kinetic energy, let's find the velocity for t = 3 s

          v = - 2 sin (t-2)

          v = -2 sin (3-2)

          v = - 1.683 m / s

body mass is m = 1 kg

we calculate

          K = ½ m v²

          K = ½ 1 (-1.683) ²

          K = 1.42 J

Answer:

The height of the cliff is 27.02 m

Explanation:

Given;

height above the ground from which the arrow is shot, h₁ = 1.5 m

initial velocity of the projectile, v = 30 m/s

angle of projection, θ = 60⁰

time taken to reach top of the cliff, t = 4.0 s

The vertical component of the velocity is calculated as;

[tex]v_y = v \times sin(\theta)\\\\v_y = 30 \times sin(60)\\\\v_y = 25.98 \ m/s[/tex]

The height attained by the projectile at the given time is calculated as;

[tex]h_2= v_y t - \frac{1}{2}gt^2\\\\h_2 = 25.98\times 4 \ - \ \frac{1}{2} \times 9.8\times 4^2\\\\h_2= 103.92 \ - \ 78.4 \\\\h_2 = 25.52 \ m[/tex]

The height of the cliff is calculated as;

H = h₁ + h₂

H = 1.5 m  +  25.52 m

H = 27.02 m

Answer:

The minimum distance between two points on the  object that are barely resolved is 0.26 mm

The corresponding distance between the  image points = 0.0015 m

Explanation:

Given  

focal length f = 50 mm and maximum aperture f>2

s =  9.0 m

aperture = 25 mm = 25 *10^-3 m

Sin a = 1.22 *wavelength /D  

Substituting the given values, we get –  

Sin a = 1.22 *600 *10^-9 m /25 *10^-3 m

Sin a = 2.93 * 10 ^-5 rad

Now  

Y/9.0 m = 2.93 * 10 ^-5

Y = 2.64 *10^-4 m = 0.26 mm

Y’/50 *10^-3 = 2.93 * 10 ^-5  

Y’ = 0.0015 m

Answer:

The correct solution is "11.51 mA".

Explanation:

Given:

Time average power,

[tex]P_{avg}=0.05 \ W/m^2[/tex]

n = 377

As we now,

⇒ [tex]P_{avg}=\frac{E_0^2}{n}[/tex]

or,

⇒ [tex]E_0^2=0.05\times 377[/tex]

⇒       [tex]=4.341 \ V[/tex]

hence,

⇒ [tex]H_0=\frac{E_0}{n}[/tex]

By putting the values, we get

         [tex]=\frac{4.341}{377}[/tex]

         [tex]=11.51 \ mA[/tex]

Answer:

it is energy resulting in charged particles

Electricity a form of energy resulting from the existence of charged particles (such as electrons or protons), either statically as an accumulation of charge or dynamically as a current

Answer:

a) 10.3 m/s

b) 566 N

Explanation:

[tex]v {}^{2} = {u}^{2} + 2as \\ v {}^{2} = 0 {}^{2} + 2(9.81)(5.4) \\ v = 10.3 \: ms {}^{ - 1} [/tex]

[tex]force \: = \frac{d(mv)}{dt} \\ = 55(10.293) \\ = 566 \: newtons[/tex]

The athelete velocity will be 10.3 and constant force 566 N.

The displacement that an object or particle experiences with respect to time is expressed vectorially as velocity. The meter per second (m/s) is the accepted unit of velocity magnitude (also known as speed).

Alternately, the magnitude of velocity can be expressed in centimeters per second (cm/s). Depending on how many dimensions are included, there are numerous ways to indicate the direction of a velocity vector.

The car's velocity in relation to your body is zero when you are driving. The speed of the car in relation to you if you were to stand by the side of the road is 20 m/s northward.

Therefore, The athelete velocity will be 10.3 and constant force 566 N.

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a. The force exerted by the ground on each of the front wheels is 4918.16 Newton.

b. The force exerted by the ground on each of the back wheels is 2627.84 Newton.

Given the following data:

a. To determine the force exerted by the ground on each of the front wheels:

First of all, we would take moment about the rear wheels.

[tex]F(3.13) - 1540(9.8) \times (3.13 - 1.09) = 0\\\\3.13F - 15092 \times 2.04 =0\\\\3.13F -30787.68=0\\\\F=\frac{30787.68}{3.13}[/tex]

Force, F = 9836.32 Newton

For each front wheel:

[tex]Force = \frac{9836.32}{2}[/tex]

Force = 4918.16 Newton.

b. To determine the force exerted by the ground on each of the back wheels:

We would determine the sum of the vertical forces acting on the wheels.

[tex]9836.32 + B - 1540(9.8) = 0\\\\9836.32 + B - 15092 = 0\\\\B=15092-9836.32[/tex]

B = 5255.68 Newton.

For each back wheel:

[tex]Force = \frac{5255.68}{2}[/tex]

Force = 2627.84 Newton.

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Answer:

y = 5 cos 2πt

Explanation:

We will use the formula for simple harmonic motion curve where;

y = a cos ωt

Where;

a is amplitude

t is period

ω is angular frequency with the formula; ω = 2π/t

We are told that when the spring is compressed, the mass is located 5 cm above its rest position.

Thus;

a = 5 cm

it's highest point is 5 cm, but we are told that after 1/2 second of being released, it reaches its lowest point.

Since highest point is 5, then lowest point will be -5.

The difference in time between the highest and lowest point is ½ s. Which is half of the period.

Thus;

t/2 = ½

Thus, t = 1 s

Now, we know that;

t = 1/f = 2π/ω

Since t = 1, then 1 = 1/f

f = 1

Thus;

2π/ω = 1

Thus, ω = 2π

Thus, the equation is;

y = 5 cos 2πt

The equation that describes the motion of the mass is y = 5 cos 2πt.

The given parameters;

The general equation of the wave is given as;

[tex]y = A\ cos\ \omega t[/tex]

where;

The angular speed of the mass is calculated as;

[tex]\omega = 2\pi f\\\\[/tex]

The period of the oscillation is calculated as;

[tex]T = 2t \\\\T = 2(0.5 s) = 1 \ s[/tex]

The frequency of the wave is calculated as;

[tex]f = \frac{1}{T} \\\\f = \frac{1}{1} \\\\f = 1\ Hz[/tex]

The equation that describes the motion of the mass is calculated as;

[tex]y = A\ cos \ \omega t\\\\y = A\ cos \ 2\pi ft\\\\y = 5\ cos \ 2\pi (1) t\\\\y = 5 \ cos \ 2\pi t[/tex]

Thus, the equation that describes the motion of the mass is y = 5 cos 2πt.

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