a 25 kg crate is pushed horizontally with a force of 70N. if the coefficient of friction is .20, calculate the acceleration of the crate.

Answer:

I don't know what you mean about which changes occurred in this process but if its why the dough starts rising then its caused by the carbon dioxide in baking soda and yeast which is a fungus

Answer:

When baking,flour is mixed with water,the other ingredients and yeast to form a paste called a dough.what happens is that the zymase enzyme from the yeast acts on the sugars to form carbon dioxide and alcohol.the carbon dioxide begins to form bubbles in the dough causing it to rise..

I hope this helps

Answer:

A concave mirror, or converging mirror, has a reflecting surface that is recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point. They are used to focus light.

Answer:

The induced current direction as viewed is clockwise

Explanation:

Lenz's Law states that the induced e. m. f. causes current to be driven in the loop of wire in such a way as to generate magnetic field that are oppose the magnetic flux change which is the source of the induced current

Therefore, as the magnet approaches the coil with the south pole,  the coil produces current equivalent to the upward movement of the south pole of a permanent magnet through it which according to Flemings Right Hand Rule is clockwise

Therefore;

The direction of the induced current in the loop (as viewed from above, looking down the magnet) is clockwise

Answer:

a)water is turning into ice it is changing it's state from liquid to solid

b)B to C  ice is melting and it  is changing  it's state from solid to liquid

C to D water is boiling and it is changing it's state from liquid to vapours(steam)

c) temperature

At A 0

At B 0

At C 100

At D 100

Explanation: The temperature will remain 0 degrees Celsius until all the ice becomes water and the temperature will remain 100 degrees Celsius until all the  water changes into steam.

Answer:

Explanation:

Discount the time here; it's not important. It doesn't tell you how long it takes the car to stop, it only refers to reaction time, which means nothing in the scheme of things.

The useful info is as follows:

initial velocity = 20 m/s

final velocity = 0 m/s

a = -10 m/s/s

and we are looking for the displacement. Use the following equation:

[tex]v^2=v_0^2+2a[/tex]Δx

where v is the final velocity, v₀ is the initial velocity, a is the deceleration (since it's negative), and Δx is displacement. Filling in:

[tex]0^2=(20)^2+2(-10)[/tex]Δx and

0 = 400 - 20Δx and

-400 = -20Δx so

Δ = 20 meters

The answer is definitely Potassium

Answer:

Frequencia = 1.25 Hz

Explanation:

Dados los siguientes datos;

Para encontrar la frecuencia de la onda;

Matemáticamente, la velocidad de una onda viene dada por la fórmula;

[tex] Velocidad = Longitud \; de \; onda * Frequencia [/tex]

Haciendo de la frecuencia el tema de la fórmula, tenemos;

[tex] Frequencia = \frac {Velocidad}{Longitud \; de \; onda} [/tex]

Sustituyendo en la fórmula, tenemos;

[tex] Frequencia = \frac {50}{40} [/tex]

Frequencia = 1.25 Hz

Answer:

The speed of the comet at the surface of the star is approximately 1,208,694.7 m/s

Explanation:

Question parameter obtained online; The mass of the star, M = 5 × 10³¹ kg

Explanation;

The given mass of the comet, m = 2 × 10⁸ kg

The initial velocity of the comet, v → 0

The distance of the comet from the star, d = 700,000,000 km

The gravitational potential at d = G·M·m/d

The kinetic energy of the comet, K.E. = m·v²/2

The kinetic energy of the comet at d = m·(0)²/2 = 0

The gravitational potential at the surface of the star, R = G·M·m/R

The kinetic energy of the comet at the surface of the star, R = m·(v)²/2 = 0

Where;

M = The mass of the star = 5 × 10³¹ kg

[tex]M_{Sun}[/tex] = The mass of the Sun = 1.989 × 10³⁰ kg

M/[tex]M_{Sun}[/tex] = 5 × 10³¹/(1.989 × 10³⁰) ≈ 25

G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²

R = The radius of the star

Therefore, we have;

m·(0)²/2 - G·M·m/d = m·v²/2 - G·M·m/R

∴ v = √((G·M·m/R - G·M·m/d)×2/m) = √(2·G·M(1/R - 1/d))

Therefore; v = (2 × 6.67430 × 10⁻¹¹ × 5 × 10³¹ × (1/R - 1/700,000,000,000))

v = 81696389149.1×√(1/R - 1/700,000,000,000).

The speed of the comet at the surface of the star, v = 81696389149.1×√(1/R - 1/700,000,000,000)

The mass radius relationship is given as follows;

[tex]\dfrac{R}{R_{Sun}} = 1.30 \times \left(\dfrac{M}{M_{Sun}} \right)^{\dfrac{1}{2} }[/tex]

[tex]R = R_{Sun} \times 1.30 \times \left(\dfrac{M}{M_{Sun}} \right)^{\dfrac{1}{2} }[/tex]

The radius of the Sun = 696,340,000 M

∴ R ≈ 696,340,000 × 1.3 × √(25.14) = 4538865694.76

R = 4538865694.76 m

v = 81696389149.1×√(1/4538865694.76 - 1/700,000,000,000) ≈ 1208694.7  m/s

AnswerIt is continuously falling towards the surface of the earth

Explanation:

since gravity from earth is the thing that keeps it constantly in orbit

Answer:

Explanation:

Because vectors have direction and x and y components you can't just add them and say that their length is 16 because A is 8 units and so is B. What you're actually finding is the magnitude and direction of the vector that results from this addition. The magnitude is the length of the resultant vector, which comes from the x and y components of A and B, and the direction is the angle between the resultant vector and the positive x axis. To add the vectors, then, we need to find the x and y components of each. We'll do the x components of A and B first so we can add them to get the x component of C. Since x values are directly related to cos, the formula to find the x components of vectors is

[tex]V_x=Vcos\theta[/tex] which is the magnitude of the vector (its length) and the angle. Finding the x components of A:

[tex]A_x=8.0cos45[/tex] so

[tex]A_x=5.7[/tex] and for B:

[tex]B_x=8.0cos180[/tex] since the negative x axis is the 180 degree axis and

[tex]B_x=-8.0[/tex] If we add them, we get

[tex]C_x=-2.3[/tex]

Now onto the y components. The formula for that is almost the same as the x components except use sin instead of cos:

[tex]A_y=8.0sin45[/tex] so

[tex]A_y=5.7[/tex] and

[tex]B_y=8.0sin180[/tex] so

[tex]B_y=0[/tex] If we add them, we get

[tex]C_y=5.7[/tex]

Now for the final magnitude:

[tex]C_{mag}=\sqrt{(-2.3)^2+(5.7)^2}[/tex] and

[tex]C_{mag}=6.1 units[/tex] and now onto the direction.

The x component of C is positive and the y component is negative, which means that the direction has us at an angle is quadrant 2; we add 180 to whatever the angle is. Finding the angle:

[tex]tan^{-1}(\frac{C_y}{C_x})=(\frac{5.7}{-2.3})[/tex] = -68 + 180 = 112 degrees

The resultant vector of A + B has a magnitude of 6.1 and a direction of 112°

Do the same thing for subtraction, except if you're subtracting B from A, the direction that B is pointing has to go the opposite way. That means that A doesn't change anything at all, but B is now pointing towards 0.

[tex]A_x=5.7[/tex] (doesn't change from above)

[tex]B_x=8.0cos0[/tex] and

[tex]B_x=8.0[/tex] so

[tex]C_x=13.7[/tex] and

[tex]A_y=5.7[/tex] (also doesn't change from above)

[tex]B_y=8.0sin0[/tex] so

[tex]B_y=0[/tex] and

[tex]C_y=5.7[/tex] and for the magnitude:

[tex]C_{mag}=\sqrt{(13.7)^2+(5.7)^2[/tex] so

[tex]C_{mag}=15units[/tex] and for the direction:

[tex]tan^{-1}(\frac{5.7}{13.7})=23[/tex] and since both x and y components of C are in Q1, we add nothing.

And you're done!!!

Answer:

The maximum velocity is 1.58 m/s.

Explanation:

A spring pendulum with stiffness k = 100N/m is attached to an object of mass m = 0.1kg, pulls the object out of the equilibrium position by a distance of 5cm, and then lets go of the hand for the oscillating object. Calculate the achievable vmax.

Spring constant, K = 100 N/m

mass, m = 0.1 kg

Amplitude, A = 5 cm = 0.05 m

Let the angular frequency is w.

[tex]w = \sqrt{K}{m}\\\\w = \sqrt{100}{0.1}\\\\w = 31.6 rad/s[/tex]

The maximum velocity is

[tex]v_{max} = w A\\\\v_{max} = 31.6\times 0.05 = 1.58 m/s[/tex]

Answer:

B. It has mass

Explanation:

The Newtons Universal gravitacion law is : F = G.[tex]\frac{m1 m2}{d^{2} }[/tex]  , where F is the force exerted , m1 and m2 are the earth's mass and the object's mass, d is the distance and G the gravitacional constant. Comparing to the options we can say that the Earth exerts a gravitational force on objects on its surface because of its mass.

Answer:

It's a pretty simple suvat linear projectile motion question, using the following equation and plugging in your values it's a pretty trivial calculation.

V^2=U^2+2*a*x

V=0 (as it is at max height)

U=30ms^-1 (initial speed)

a=-g /-9.8ms^-2 (as it is moving against gravity)

x is the variable you want to calculate (height)

0=30^2+2*(-9.8)*x

x=-30^2/2*-9.8

x=45.92m

Answer:

35

Explanation:

dfddffffffffffffdddfr

Yes it is the measurement in science

Answer:

I_syst = 278.41477 kg.m²

Explanation:

Mass of platform; m1 = 117 kg

Radius; r = 1.61 m

Moment of inertia here is;

I1 = m1•r²/2

I1 = 117 × 1.61²/2

I1 = 151.63785 kg.m²

Mass of person; m2 = 62.5 kg

Distance of person from centre; r = 1.05 m

Moment of inertia here is;

I2 = m2•r²

I2 = 62.5 × 1.05²

I2 = 68.90625 kg.m²

Mass of dog; m3 = 28.3 kg

Distance of Dog from centre; r = 1.43 m

I3 = 28.3 × 1.43²

I3 = 57.87067 kg.m²

Thus,moment of inertia of the system;

I_syst = I1 + I2 + I3

I_syst = 151.63785 + 68.90625 + 57.87067

I_syst = 278.41477 kg.m²

Answer:

Explanation:

The first part of this question is simply asking us to convert the speed from miles per hour to meters per second:

[tex]60.0\frac{mi}{hr}*\frac{1hr}{3600sec}*\frac{1609.34m}{1mi}=26.8\frac{m}{s}[/tex] choice C.

The next part wants us to use the equation for acceleration and find the acceleration:

[tex]a=\frac{v-v_0}{t}[/tex] where v is final velocity, v0 is initial velocity, and t is time in seconds (which was one of the reasons we had to convert the initial velocity from 60.0 mph to m/s):

[tex]a=\frac{26.8-0}{2.5}[/tex] and

a = 10.7 m/s/s, choice B.

Answer:

The answer is ( D) i. e both b and c.

B

Explanation:

BECAUSE IT WAS GOING UPWORD THEN IT'S VELOCITY WAS DECREASING -10MS¹

Answer:

Explanation:

From physics, which is directly related to math (especially when it comes to parabolic motion!), we learn that at the very top of the parabola the object has to stop for a millisecond so it can turn around and fall back to earth. This translates to a velocity of 0 at its highest point. So B.

Answer:

may be d)45°

Explanation:

Answer:

A

Explanation:

i think a is the answer because if you take an example of group 1 and 2 metals on the periodic table you will notice that they are highly reactive but they have a few electrons in their outer most shells.

I hope this helps

Answer:

750 w : time = 1hour

Explanation:

750x1hour

=750 watt-hours

Answer:

Following are the response to the given question:

Explanation:

[tex]F_2=mgh_2+\frac{1}{2}mv_2^2+\frac{1}{2}mR^2(W)^2\\\\\therefore \\\\ \to WR=v_2\\\\E_2=Mgh_2+MV_2^2[/tex]

Answer:

     i =[tex]- \frac{r \ A'}{2 \ rho}[/tex] ,  i =  0.92   A

Explanation:

This exercise asks for the electromotive force, which can be calculated with Faraday's law

          fem = [tex]- \frac{d \Phi_B }{dt}[/tex]

where the magnetic flux

          Ф = B. A

bold letters indicate vectors. We can write this equation

          Ф = B A cos θ

In this case the magnetic field is perpendicular to the page and the normal to the loop of the loop is also parallel to the page, therefore the angle is zero and the cosine is 1

the loop is

          A = π r²

we substitute in the first equation

          fem = - π r² [tex]\frac{dB}{dt}[/tex]

we substitute the values

          fem = -π r² 1

          fem = - π r²

to calculate the current let's use ohm's law

           V = i R

            R = ρ L / A'

where A 'is the area of ​​the wire and L is the length of the loop

            L = 2π r

            V = i (ρ 2π r / A ')

            I = [tex]\frac{V \ A'}{2\pi \ r \ rho}[/tex]

In this case

           V = fem

           I = fem / R            

           i =[tex]- \frac{r \ A'}{2 \ rho}[/tex]

In order to complete the calculation, you need the radius of the loop and / or the wire cutter.

if we assume that the loop has a radius of r = 1 cm = 0.01 m and an area of ​​the wire   A'= π 10⁻⁶ m²   a radius of the wire 1 mm

           i = - 10⁻² π 10⁻⁶ / ( 2 1.7 10-8)

           i =  0.92   A

Complete Question:

A long distance runner running a 5.0km track is pacing himself by running 4.5km at 9.0km/hr and the rest at 12.5km/hr. What is the average speed?​

Answer:

Average speed = 9.7333 km/h

Explanation:

Given the following data;

To find the average speed;

First of all, we would determine the time taken to cover distance A in speed A by using the formula;

[tex] Time \ A = \frac {Distance \; A}{Speed \; A} [/tex]

Substituting the values into the formula, we have;

[tex] Time \ A = \frac {4.5}{9.5} [/tex]

Time A = 0.4737 hours

Total distance = distance A + distance B

5 = 4.5 + distance B

Distance B = 5 - 4.5

Distance B = 0.5 Km

Next, we would determine the time to cover distance B in speed B;

[tex] Time \ B = \frac {0.5}{12.5} [/tex]

Time A = 0.04 hours

Total time = time A + time B

Total time = 0.4737 + 0.04

Total time = 0.5137 hours

Now, we would solve for the average speed;

Mathematically, the average speed of an object is given by the formula;

[tex] Average \; speed = \frac {total \; distance}{total \; time} [/tex]

[tex] Average \; speed = \frac {5}{0.5137} [/tex]

Average speed = 9.7333 km/h

Answer:

Option D. 9.47 V

Explanation:

We'll begin by calculating the equivalent resistance of the circuit. This can be obtained as follow:

Resistor 1 (R₁) = 20 Ω

Resistor 2 (R₂) = 30 Ω

Resistor 3 (R₃) = 45 Ω

Equivalent Resistance (R) =?

R = R₁ + R₂ + R₃ (series connections)

R = 20 + 30 + 45

R = 95 Ω

Next, we shall determine the current in the circuit. This can be obtained as follow:

Voltage (V) = 45 V

Equivalent Resistance (R) = 95 Ω

Current (I) =?

V = IR

45 = I × 95

Divide both side by 95

I = 45 / 95

I = 0.4737 A

Finally, we shall determine, the voltage across R₁. This can be obtained as follow:

NOTE: Since the resistors are in series connection, the same current will pass through them.

Current (I) = 0.4737 A

Resistor 1 (R₁) = 20 Ω

Voltage 1 (V₁) =?

V₁ = IR₁

V₁ = 0.4737 × 20

V₁ = 9.47 V

Therefore, the voltage across R₁ is 9.47 V.

Answer:

9.47

Explanation:

Just Took the Test

Answer:

the child with the smallest area will be the one who sinks

Explanation:

The child who will sink to the ground is the one who exerts the greatest pressure on the ground, even though the force, which in this case is equal to the weight, is equal.

Pressure is defined by

           P = F / A

in this case the strength of the children is their weight

           F = W

           P = W / A

therefore the pressure changes are in the area of ​​contact with the ground, the child with the smallest area will be the one who sinks

Answer:

The rate of change of distance is called speed it can also be defined as distance travelled per unit time,from these definition you can tell that the formula will be

speed=distance/time

in this question the distance is 900meters and the time is 55seconds therefore the speed will be:

s=900meters/55seconds

=16.36m/s

I hope this helps

Explanation:

Ultrasound refers to sound waves having frequencies greater than the frequency range limit. Ultrasound has the same physical qualities as "regular" (audible) music, except that individuals cannot hear it. Ultrasound devices use frequencies ranging from 20 kHz to a few gigahertz.

The frequencies of ultrasound utilised in clinical settings are generally between 2 and 12 MHz. Shorter wavelengths have a larger penetration depth into the body but less resolution; longer wavelengths have a greater depth of penetration but have a restricted depth of penetration.

Answer:

16.6 °C

Explanation:

From the question given above, the following data were obtained:

Temperature at upper fixed point (Tᵤ) = 100 °C

Resistance at upper fixed point (Rᵤ) = 75 Ω

Temperature at lower fixed point (Tₗ) = 0 °C

Resistance at lower fixed point (Rₗ) = 63.00Ω

Resistance at room temperature (R) = 64.992 Ω

Room temperature (T) =?

T – Tₗ / Tᵤ – Tₗ = R – Rₗ / Rᵤ – Rₗ

T – 0 / 100 – 0 = 64.992 – 63  / 75 – 63

T / 100 = 1.992 / 12

Cross multiply

T × 12 = 100 × 1.992

T × 12 = 199.2

Divide both side by 12

T = 199.2 / 12

T = 16.6 °C

Thus, the room temperature is 16.6 °C