Question 4 of 10 A student measures the time it takes for two reactions to be completed. Reaction A is completed in 39 seconds, and reaction B is completed in 50 seconds. What can the student conclude about the rates of these reactions? A. The rate of reaction B is higher B. The rate of reaction A is higher. C. The rates of reactions A and B are equal.​

The question is incomplete. The complete question is :

A plate of uniform areal density [tex]$\rho = 2 \ kg/m^2$[/tex] is bounded by the four curves:

[tex]$y = -x^2+4x-5m$[/tex]

[tex]$y = x^2+4x+6m$[/tex]

[tex]$x=1 \ m$[/tex]

[tex]$x=2 \ m$[/tex]

where x and y are in meters. Point [tex]$P$[/tex] has coordinates [tex]$P_x=1 \ m$[/tex] and [tex]$P_y=-2 \ m$[/tex]. What is the moment of inertia [tex]$I_P$[/tex] of the plate about the point [tex]$P$[/tex] ?

Solution :

Given :

[tex]$y = -x^2+4x-5$[/tex]

[tex]$y = x^2+4x+6$[/tex]

[tex]$x=1 $[/tex]

[tex]$x=2 $[/tex]

and [tex]$\rho = 2 \ kg/m^2$[/tex] , [tex]$P_x=1 \ $[/tex] , [tex]$P_y=-2 \ $[/tex].

So,

[tex]$dI = dmr^2$[/tex]

[tex]$dI = \rho \ dA \ r^2$[/tex]  ,           [tex]$r=\sqrt{(x-1)^2+(y+2)^2}$[/tex]

[tex]$dI = (\rho)((x-1)^2+(y+2)^2)dx \ dy$[/tex]

[tex]$I= 2 \int_1^2 \int_{-x^2+4x-5}^{x^2+4x+6}((x-1)^2+(y+2)^2) dy \ dx$[/tex]

[tex]$I= 2 \int_1^2 \int_{-x^2+4x-5}^{x^2+4x+6}(x-1)^2+(y+2)^2 \ dy \ dx$[/tex]

[tex]$I=2 \int_1^2 \left( \left[ (x-1)^2y+\frac{(y+2)^3}{3}\right]_{-x^2+4x-5}^{x^2+4x+6}\right) \ dx$[/tex]

[tex]$I=2 \int_1^2 (x-1)^2 (2x^2+11)+\frac{1}{3}\left((x^2+4x+6+2)^3-(-x^2+4x-5+2)^3 \ dx$[/tex]

[tex]$I=\frac{32027}{21} \times 2$[/tex]

  [tex]$= 3050.19 \ kg \ m^2$[/tex]

So the moment of inertia is  [tex]$3050.19 \ kg \ m^2$[/tex].

Answer:

Dont know if this is right but i say C

Explanation:

Answer:

C. an added force of 20 N toward one side of the hill

Explanation:

I just took the quiz and got it correct./

Answer:

[tex]1.056[/tex]

Explanation:

v = Velocity of sound = 342 m/s

[tex]v_s[/tex] = Velocity of source of sound = 9.3 m/s

[tex]f_a[/tex] = Frequency when car is approaching

[tex]f_m[/tex] = Frequency when car is moving away

[tex]f_s[/tex] = Frequecy of source of sound

The required ratio is

[tex]\dfrac{f_a}{f_m}=\dfrac{\dfrac{v}{v-v_s}f_s}{\dfrac{v}{v+v_s}f_s}\\\Rightarrow \dfrac{f_a}{f_m}=\dfrac{v+v_s}{v-v_s}\\\Rightarrow \dfrac{f_a}{f_m}=\dfrac{342+9.3}{342-9.3}\\\Rightarrow \dfrac{f_a}{f_m}=1.056[/tex]

The ratio of the frequency you hear while the car is approaching to the frequency you hear while the car is moving away is [tex]1.056[/tex]

Seasonal change in the angle of sunlight, caused by the tilt of the Earth's axis, is the basic mechanism that results both in warmth of the weather and in length of the day.

Answer:There are numerous benefits to mountaineering. The most obvious benefits are improving both your physical fitness and cardiovascular fitness levels as well as reducing body fat through aerobic exercise.

Explanation: trust

Answer:

Lower your risk of heart disease. Improve your blood pressure and blood sugar levels. Boost bone density, since walking is a weight-bearing exercise.

Answer:

3.33m

Explanation:

λ = C/f

Where,

λ (Lambda) = Wavelength in meters

c = velocity=1.5m/s

f = Frequency=0.45

λ = 1.5/0.45

=3.33m.

Explanation:

First, the liquid on the bottom of the pot closest to the heat source starts to get hot; as it does, it rises. The rising hot water is replaced by the cooler, more dense water molecules. The water molecules in your pot continually exchange in this way, thanks to gravity, eventually warming the entire pot of liquid.

Answer:

Spring constant = 48 N/m

Explanation:

Given the following data;

Mass = 0.60 kg

Force = 1.2 N

Distortion = 0.025 m

To find the spring constant;

Mathematically, the force exerted on a spring to cause a distortion or an extension is given by the formula;

Force = spring constant * distortion

Substituting into the formula, we have;

1.2 = spring constant * 0.025

Spring constant = 1.2/0.025

Spring constant = 48 N/m

You just said that the crests of the incoming waves are 4m apart.

That's it ! That's the wavelength. The distance between crests. It doesn't matter how often they sail past you.

The question I was expecting here: How fast are the waves traveling ?

That's (frequency)x(wavelength). 8 m/s.

Answer:

The answer is "[tex]17.28 \times 10^{-14}\ A[/tex]"

Explanation:

Calculating the number of electrons passing in per second:

[tex]\to n_e = \frac{4910}{0.0758} = 6.4 \times 10^5[/tex]

Calculating the current in electron:

[tex]\to I_e = 6.4 \times 10^5 \times 1.6 \times 10^{-19} = 10.24 \times 10^{-14}\ A[/tex]

Calculating the number of protons passing in per second:

[tex]\to n_p = \frac{2583}{0.0577} = 4.4 \times 10^{4}[/tex]

Calculating the current in proton:

[tex]\to I_p = 4.4 \times 10^{4} \times 1.6 x 10^{-19} = 7.04 \times 10^{-14} \ A[/tex]

Calculating the total current:

[tex]\to I = I_p + I_e = 17.28 \times 10^{-14}\ A[/tex]

Answer:

Final speed after 2 seconds = 34.6 m/s

Explanation:

Given:

Initial speed of coin (u) = 15 m/s

Time taken = 2 seconds

Find:

Final speed after 2 seconds

Computation:

Gravitational acceleration of earth = 9.8 m/s²

Using first equation of motion;

v = u + at

or

v = u + gt

where,

v = final velocity

u = initial velocity

g = Gravitational acceleration

t = time taken

v = 15 + 9.8(2)

v = 15 + 19.6

Final speed after 2 seconds = 34.6 m/s

Answer:

Distance is 100m, displacement is 0m

Explanation:

Distance is how much you travelled in total (100m)

Displacement is when you compare your final and initial positions.

It is usually Final position - Initial position.

Since you start and finish at the same point, it would be 0 - 0 = 0m

So the displacement is 0m.

Answer:

please give me brainlist and follow

Explanation:

At the bottom of the hill, the baby carriage will likely have less momentum Therefore, option D is correct. Solution: ... Therefore, at the bottom of the hill, the heavy truck will have more momentum and baby carriage will have less momentum.

Answer: The mass of ball is 10 grams.

Explanation:

Given : Kinetic energy = 4.5 J

Velocity = 30 m/s

The formula for Kinetic energy is as follows.

[tex]K.E = \frac{1}{2}mv^{2}[/tex]

where,

K.E = Kinetic energy

m = mass

v = velocity

Substitute the values into above formula as follows.

[tex]K.E = \frac{1}{2}mv^{2}\\4.5 J = \frac{1}{2} \times m \times (30 m/s)^{2}\\m = \frac{4.5 J \times 2}{900 m^2/s^2} (1 Js^{2} = kg m^{2})\\= 0.01 kg (1 kg = 1000 g)\\= 10 g[/tex]

Thus, we can conclude that the mass of ball is 10 grams.

Answer:

True

Explanation:

Average speed is the rate at which an object is moving at a given instant in time.

Answer: false.

Explanation: i’m pretty sure that’s instantaneous speed.

Answer:

lowers :)

Explanation:

Answer:

Series

Cells in Series connection.In series, cells are joined end to end so that the same current flows through each cell. In case if the cells are connected in series the emf of the battery connected to the sum of the emf of the individual cell,If E is the overall emf of the battery combined with n number cells and E1, E2,......Em is the EMFs of individual cell.

Then   

E= E1+E2+...............+Em.

The seasons in the Northern Hemisphere are the opposite of those in the Southern Hemisphere. Seasons occur because Earth is tilted on its axis relative to the orbital plane, the invisible, flat disc where most objects in the solar system orbit the sun.

Answer:

Tesla is name of a car

uu the way to go back and said that

Answer:

4.4345× 10^-7V

Explanation:

The computation of the half voltage for a 1.2T magnetic field applied is shown below

The volume of one mole of copper is

v = m ÷p

= 63.5 ÷ 8.92

= 7.12cm

Now the density of free electrons in copper is

n = Na ÷ V

= 6.02 × 10^23 ÷ 7.12

= 8.456× 10^28/m^3

Now the half voltage is

= IB ÷ nqt

= (5 × 1.20) ÷ (8.456× 10^28 × 1.6 × 10^-19 × 0.1× 10^-2)

= 4.4345× 10^-7V

Answer:

The answer is "512 J".

Explanation:

bullet mass [tex]m_1 = 10 g= 10^{-2} \ kg\\\\[/tex]

initial speed [tex]u_1 = 2\ \frac{Km}{s}= 2000\ \frac{m}{s}\\\\[/tex]

block mass [tex]m_2 = 4\ Kg[/tex]

initial speed [tex]v_2 =-4.2 \frac{m}{s}[/tex]

final speed [tex]v_2= 0[/tex]

Let [tex]v_1[/tex] will be the bullet speed after collision:

throughout the consevation the linear moemuntum

[tex]\to M_1V_1+m_2v_2=M_1U_1+m_2u_2\\\\\to (10^{-2} kg) V_1 +0 = (10^{-2} kg)(2000 \frac{m}{s}) + (4 \ kg)(-4.2 \frac{m}{s}) \\\\\ \to 10^{-2} v_1 = 20 -16.8\\\\[/tex]

                [tex]= 320 \frac{m}{s}[/tex]

The kinetic energy of the bullet in its emerges from the block

[tex]k=\frac{1}{2} m_1 v_1^2[/tex]

   [tex]=\frac{1}{2} \times 10^{-2} \times 320\\\\=512 \ J[/tex]

An example of noncontrolled substance from the option is Cough medications.

Noncontrolled substances are substances that are prescribed by medical personnel or pharmaceutical professionals for treatment of a disorder or ailments that is affecting a person.

Noncontrolled substances include medications that are majorly prescribed for treatment of medical conditions like high blood pressure, diabetes, and bacterial infections.

Therefore, An example of noncontrolled substance from the option is Cough medications.

Learn more about noncontrolled substances below.

https://brainly.com/question/5349491

Answer:

[tex]313.92\ \text{m/s}[/tex]

[tex]47.088\ \text{kg m/s}[/tex]

Explanation:

m = Mass of ball = 150 g

[tex]\theta[/tex] = Angle of kick = [tex]60^{\circ}[/tex]

[tex]x[/tex] = Displacement of ball in x direction = 12 m

Range of projectile is given by

[tex]x=\dfrac{u\sin^2\theta}{2g}\\\Rightarrow u=\dfrac{2xg}{\sin^2\theta}\\\Rightarrow u=\dfrac{2\times 12\times 9.81}{\sin^260^{\circ}}\\\Rightarrow u=313.92\ \text{m/s}[/tex]

The velocity of the ball instantly after the man kicks the ball is [tex]313.92\ \text{m/s}[/tex]

Impulse is given by

[tex]J=mu\\\Rightarrow J=0.15\times 313.92\\\Rightarrow J=47.088\ \text{kg m/s}[/tex]

The impulse of his foot on the ball is [tex]47.088\ \text{kg m/s}[/tex].

Answer:

d

Explanation:

Answer:

Kinetic energy is greater than the potential energy.

Explanation:

The potential energy stays constant because the height is not changing.  Potential energy = MGH, where m is the mass (400 kg), g is the acceleration due to gravity (9.8 m / sec2), and H is the height (1 m).  So the result is 400 * 9.8 * 1 = 3920 J

The kinetic energy = 1/2 mv2 = 0.5  * 400 kg * (5 m/sec)2 = 5000 J.  It also stays constant because the speed is not changing.

Therefore, the kinetic energy is greater than the potential energy.

Answer:

True

Explanation:

300/3=100km/hr

hope it helps. Plz mark me as brainliest.

Answer:

True

hope it helps u

thanks