6th grade science I mark as brainliest !

Answer:

Friction can stop or slow down the motion of an object.

Explanation:

The slowing force of friction always acts in the direction opposite to the force causing the motion.

Answer:

yes, we can tell if there will be rain by the swelling in rain clouds, we can also see if a tornado is forming based on the look of the wall cloud. we can use satellites to predict the amount of precipitation or wind.

Explanation:

thank you for ur generosity

Answer:W = m*g*h

19*9.8*32.4 = 6,032.9 rounded

honestly, I do not know if this is correct so please don't come back at me

hopefully this helps

Explanation: [do the following, if you think I am wrong]

just pick a formula,

plug in the number to the mass, gravity, and height

than multiply

get your answer, but don't forget to round to the nearest tenth

Answer:

mas

Explanation:

mass is the amount of space something occupies.

Answer:

-6,329.5Joules

Explanation:

Complete question:

Sally applies a horizontal force of 462N with a rope to drag a wooden crate across a floor with a constant speed the rope tied to the crate is pulled at an angle of 56.0degree and sally moves the crate 24.5m. What work is done by the floor through the force of friction between the floor and crate.

Work done = Fd cos theta

F is the horizontal force

d is the distance covered

theta angle of inclination

Substituting into the formula

Workdone  = 462(24.5)cos 56

Workdone = 11,319(0.5592)

Workdone = 6,329.5Joules

Hence the workdone by sally is 6,329.5Joules

The work done by friction will be opposite the work done by sally, hence work done by the floor through force of friction between the floor and the crate is -6,329.5Joules

Answer:

WE NEED TO ADD ALL 40+2.38 +75+5

Explanation:

PLSE GIVE SOME POINTS DUDE

Answer:

The definition of a fulcrum is a pivot point around which a lever turns, or something that plays a central role in or is in the center of a situation or activity.

Answer:

b i think so because it makes senes

Answer: When there is another magnet close by.

Explanation: The needle of a compass is itself a magnet, and thus the north pole of the magnet always points north, except when it is near a strong magnet. ... When you take the compass away from the bar magnet, it again points north. So, we can conclude that the north end of a compass is attracted to the south end of a magnet.

Answer:

4363.3231 feets²

Explanation:

Given that :

Distance, r = 50 ft

θ = 200°

The arc length of area covered :

Arc length = θ/360° * πr²

Arc length = (200/360) * 50 ft ^2 * π

Arc length = 0.5555555 * 2500 * π

Arc length = 4363.3231 feets²

Answer:

2.75 m.

Explanation:

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

Potential energy (PE) = 41772.5 J

Mass (m) of object = 1550 kg

Height (h) =?

Potential energy is the energy possess by an object due to its location. Mathematically, potential energy is expressed as shown below:

PE = mgh

Where

PE => potential energy

m => mass of the object

g => acceleration due to gravity

h => height to which the object is located.

With the above formula, we can obtain the height to which the object is located as follow:

Potential energy (PE) = 41772.5 J

Mass (m) of object = 1550 kg

Acceleration due to gravity (g) = 9.8 m/s²

Height (h) =?

PE = mgh

41772.5 = 1550 × 9.8 × h

41772.5 = 15190 × h

Divide both side by 15190

h = 41772.5 / 15190

h = 2.75 m

Thus, the object is located at 2.75 m above the ground.

Answer:

d = 106.41 m

Explanation:

Given that,

Initial speed of the car, u = 60 mph = 26.9 m/s

The deceleration in the car, a = -3.4 m/s²

The average reaction time, t = 0.218 m/s

It finally stops, final velocity, v = 0

We need to find the distance covered by the car as it come to a stop.

Using third equation of motion to find.

[tex]v^2-u^2=2ad\\\\d=\dfrac{v^2-u^2}{2a}\\\\d=\dfrac{0^2-26.9^2}{2\times (-3.4)}\\\\d=106.41 m[/tex]

So, the car will cover 106.41 m as it comes to a stop.

Answer:

Explanation:

Let n be number of total number of nucleons ( protons + neutrons )

Total mass inside nucleus =  n x 1.67 x 10⁻²⁷ Kg

volume of nucleus = 4/3 π r³

= 1.33 x 3.14 x (10⁻¹⁵)³ m

= 4.17 x 10⁻⁴⁵ m³

Density = mass / volume

=  n x 1.67 x 10⁻²⁷ / 4.17 x 10⁻⁴⁵

= .4 n x 10¹⁸ kg / m³

or of the order of 10¹⁸ kg/m³

b )

Density of iron = 7900 kg / m³

or of the order of 10⁴ kg / m³

So nucleus of a matter  is about 10¹⁴ times denser than iron .

Answer:

 t = 14.53 s

Explanation:

The speed of a wave is constant and is given by

         v = [tex]\sqrt{ \frac{B}{ \rho} }[/tex]

in this exercise they indicate that we assume the constant velocity, therefore we can use the uniform motion relations

          v = x / t

           t = x / v

in this case the sound pulse leaves the ship and must return so the distance is

          x = 2d

where d is the ocean depth d = 10900m and the speed of sound in seawater is v = 1500 m / s

let's calculate

           t = 2 10900/1500

           t = 14.53 s

Answer:

1. positive acceleration represents an object speeding up; negative acceleration represents an object slowing down

Explanation:

Acceleration is clearly defined as the rate of change of velocity with time. When are body is speeding up as we say, it is accelerating. When a body is coming to rest, it is decelerating.

Positive acceleration occurs when the speed of a moving continues to increase.

Negative acceleration is when the speed of a moving body reduces drastically.

Answer:i think it is c

Explanation:

Answer:

Explanation: i think its c to try it

Answer:

Explanation:

The electric field inside of a conductor is 0 because the conduction electrons are pushed to the outer edges of the conductor. The surface of the conductor still has charge.

C

It is right because I took this and I got this answer correct

Answer:

(a) The resistor disspates 103680 joules during a 24-hour period.

(b) The heat flux of the resistor is approximately 4340.589 watts per square meter.

(c) The fraction of heat dissipated from the top and bottom surfaces is 0.045.

Explanation:

(a) The amount of heat dissipated ([tex]Q[/tex]), measured in joules, by the cylindrical resistor is the power multiplied by operation time ([tex]\Delta t[/tex]), measured in hours. That is:

[tex]Q = \dot Q \cdot \Delta t[/tex] (1)

If we know that [tex]\dot Q = 1.2\,W[/tex] and [tex]\Delta t = 86400\,s[/tex], then the amount of heat dissipated by the resistor is:

[tex]Q = (1.2\,W)\cdot (86400\,s)[/tex]

[tex]Q = 103680\,J[/tex]

The resistor disspates 103680 joules during a 24-hour period.

(b) The heat flux ([tex]Q'[/tex]), measured in watts per square meter, is the heat transfer rate divided by the area of the cylinder ([tex]A[/tex]), measured in square meters:

[tex]Q' = \frac{\dot Q}{A}[/tex] (2)

[tex]Q' = \frac{\dot Q}{\frac{\pi}{2}\cdot D^{2}+\pi\cdot D \cdot h }[/tex] (3)

Where:

[tex]D[/tex] - Diameter, measured in meters.

[tex]h[/tex] - Length, measured in meters.

If we know that [tex]\dot Q = 1.2\,W[/tex], [tex]D = 4\times 10^{-3}\,m[/tex] and [tex]h = 2\times 10^{-2}\,m[/tex], the heat flux of the resistor is:

[tex]Q' = \frac{1.2\,W}{\frac{\pi}{2}\cdot (4\times 10^{-3}\,m)^{2}+\pi\cdot (4\times 10^{-3}\,m)\cdot (2\times 10^{-2}\,m) }[/tex]

[tex]Q' \approx 4340.589\,\frac{W}{m^{2}}[/tex]

The heat flux of the resistor is approximately 4340.589 watts per square meter.

(c) Since heat is uniformly transfered, then the fraction of heat dissipated from the top and bottom surfaces ([tex]r[/tex]), no unit, is the ratio of the top and bottom surfaces to total surface:

[tex]r = \frac{\frac{\pi}{2}\cdot D^{2}}{A}[/tex] (3)

If we know that [tex]A \approx 2.765\times 10^{-4}\,m^{2}[/tex] and [tex]D = 4\times 10^{-3}\,m[/tex], then the fraction is:

[tex]r = \frac{\frac{\pi}{2}\cdot (4\times 10^{-3}\,m)^{2} }{2.765\times 10^{-4}\,m^{2}}[/tex]

[tex]r = 0.045[/tex]

The fraction of heat dissipated from the top and bottom surfaces is 0.045.

Answer:

It's A. White light is made up of many different wavelengths of light.

Correct temperature is 80°F

Answer:

T_f = 38.83°F

Explanation:

We are given;

Volume; V = 8 ft³

Initial Pressure; P_i = 100 lbf/in² = 100 × 12² lbf/ft²

Initial temperature; T_i = 80°F = 539.67 °R

Time for outlet flow; t_o = 90 s

Mass flow rate at outlet; m'_o = 0.03 lb/s

Final pressure; P_f = 30 lbf/in² = 30 × 12² lbf/ft²

Now, from ideal gas equation,

Pv = RT

Where v is initial specific volume

R is ideal gas constant = 53.33 ft.lbf/°R

Thus;

v = RT/P

v_i = 53.33 × 539.67/(100 × 12²)

v_i = 2 ft³/lb

Formula for initial mass is;

m_i = V/v_i

m_i = 8/2

m_i = 4 lb

Now change in mass is given as;

Δm = m'_o × t_o

Δm = 0.03 × 90

Δm = 2.7 lb

Now,

m_f = m_i - Δm

Thus; m_f = 4 - 2.7

m_f = 1.3 lb

Similarly in above;

v_f = V/m_f

v_f = 8/1.3

v_f = 6.154 ft³/lb

Again;

Pv = RT

Thus;

T_f = P_f•v_f/R

T_f = (30 × 12² × 6.154)/53.33

T_f = 498.5°R

Converting to °F gives;

T_f = 38.83°F

The final temperature, in °F, of the air remaining in the tank is 38.83°F

It is given that volume V = 8 ft³

Initial Pressure Pi = 100 lbf/in² = 100 × 12² lbf/ft²

Initial temperature Ti = 80°F = 539.67 °R

Time for outlet flow; to = 90 s

Mass flow rate at outlet; m'o = 0.03 lb/s

Final pressure; Pf = 30 lbf/in² = 30 × 12² lbf/ft²

Now, from ideal gas equation,

Pv = RT

where v is initial volume, R is ideal gas constant = 53.33 ft.lbf/°R

[tex]v = RT/P\\ \\ v_i = 53.33 *539.67/(100*12^2)\\ \\ v_i = 2 ft^3/lb [/tex]

The initial mass is;

[tex]m_i = V/v_i\\ \\ m_i = 8/2\\ \\ m_i = 4 lb [/tex]

Now change in mass is given as;

Δm = [tex]m'_o*t_o[/tex]

Δm = 0.03 × 90

Δm = 2.7 lb

[tex]m_f[/tex] = [tex]m_i[/tex] - Δm

[tex]m_f[/tex] = 4 - 2.7

[tex]m_f[/tex] = 1.3 lb

now,

[tex]v_f = V/m_f\\ \\ v_f = 8/1.3\\ \\ v_f = 6.154 f^3/lb [/tex]

From the gas equation

Pv = RT

Final state:

[tex]T_f = P_fv_f/R\\\\ T_f = (30*12^2*6.154)/53.33\\\\ T_f = 498.5^oR [/tex]

Converting to °F:

[tex]T_f[/tex] = 38.83°F is the final temperature.

Learn More:

https://brainly.com/question/18518493

Answer:

7.5 × 10^14 Hz

Velocity of light = 3×10^8m/s

Frequency = (3×10^8)/(4 x 10^-7)

= 7.5 × 10^14 Hz

Answer:

F = 233.52 N,  θ' = 351.41º

Explanation:

In this exercise we must find the net force applied on the donkey.

For this we use Newton's second law, where we create a reference frame with the horizontal x axis

let's decompose the forces

Jack

        = 80.5 N

Jill

       cos 45 = F_{2x} / F₂2

       sin 45 = F_{2y} / F₂2

       F_{2x} = F₂ cos 45

       F_{2y} = F₂ sin 45

       F_{2x} = 81.7 cos 45 = 57.77 N

       F_{2y} = 81.7 sin 45 = 57.77 N

Jane

      cos (270 + 45) = F_{3x} / F₃3

      sin 315 = F_{3y} / F₃

      F_{3x} = 131 cos 315 = 92.63 N

      F_{3y} = 131 sin 315 = -92.63 N

the force can be found in each axis

X axis

         F_{x} = F_{1x} + F_{2x} + F_{3x}

         F_{x} = 80.5 +57.77 + 92.63

         F_{x} = 230.9 N

Axis y

         F_{y} = F_{1y} + F_{2y} + F_{3y}

         F_{y} = 0 + 57.77 -92.63

         F_{y} = -34.86 N

we can give the result in two ways

a) F = (230.9 i ^ - 34.86 j ^) N

b) in the form of module and angle

we use the Pythagorean theorem

         F = √(Fₓ² + F_{y}²

        F = √(230.9² + 34.86²)

        F = 233.52 N

let's use trigonometry for the angle

        tan θ = [tex]\frac{F_y}{F_x} }[/tex]

        θ = tan⁻¹ (\frac{F_y}{F_x} })

        θ = tan⁻¹ (-34.86 / 230.9)

        θ = -8.59º

if we measure this angle from the positive side of the x-axis counterclockwise

          θ' = 360 -θ

          θ‘= 360- 8.59

          θ' = 351.41º

Answer:

The political actions that led to successful conservation in both stories were what they call an FC company that makes the forest industry true. They make it out of a factory and it can make it very successful and accomplished.

Explanation:

Answer:

The answer is B .........number 2

Explanation:

Answer:

a) v₀ₓ = 62.76 m / s, b)   θ₁ = 17.6º,   θ₂ = 67.0º

Explanation:

We can solve this exercise using the projectile launch ratios

a) Let's find the time it takes for the bullet to reach the water level

       y = y₀ + v_{oy} t - ½ g t²

when it reaches the water its height is zero y = 0, as the bullet is fired horizontally its initial vertical velocity is zero

       0 = y₀ + 0 - ½ g t²

       t =[tex]\sqrt{2y_o/g}[/tex]

       t = [tex]\sqrt{2 \ 7 /9.8}[/tex]          

       t = 1,195 s

now we can calculate the speed with the horizontal movement

        x = v₀ₓ t

        v₀ₓ = x / t

        v₀ₓ = 75.0 / 1.195

        v₀ₓ = 62.76 m / s

b) if the speed of the bullets is half of that found

         v₀ = 62.76 / 2 = 31.38 m / s

let's write the expressions for the distance

          x = v₀ cos θ t

          y = y₀ + v_{oy} sin θ t - ½ g t²

          t = [tex]\frac{x}{v_o \ cos \theta}[/tex]

we substitute

          [tex]0 = y_o + v_o sin \theta \ \frac{x}{v_o \cos \thetay} - 1/2 g \ (\frac{x}{v_o \ cos \theta})^2[/tex]

          [tex]0 = y_o + x tan \theta - \frac{1}{2} g \ \frac{x^2}{ v_o^2 \ cos^2 \theta}[/tex]    

let's use the identified trigonometry

          sec² θ = 1 + tan² θ

         sec θ = 1 / cos θ

we substitute

          [tex]0 = y_o + x tan \theta - \frac{g x^2}{2 v_o^2} ( 1 + tan^2 \theta)[/tex]

          [tex]\frac{g x^2}{2v_o^2} tan^2 \theta - x tan \theta + \frac{gx^2}{2v_o^2} - y_o = 0[/tex]

we change variable

         tan θ = H

         [tex]\frac{gx^2}{2 v_o^2 } H^2 - x H + \frac{gx^2}{2v_o^2}-y_o =0[/tex]

we subtitle the values

         [tex]\frac{9.8 \ 75^2}{2 \ 31.38^2} H^2 - 75 H + \frac{9.8 \ 75^2}{2 \ 31.38^2}-7 =0[/tex]

         27.99 H² - 75 H + 20.99 = 0

         H² - 2.679 H + 0.75 = 0

we solve the quadratic equation

         H = [2.679 ± [tex]\sqrt{2.679^2 - 4 0.75}[/tex]] / 2

         H = [2,679 ± 2,044] / 2

         H₁ = 0.3175

         H₂ = 2.3615

now we can find the angles

          H₁ = tan θ₁

          θ₁ = tan⁻¹ H₁

          θ₁ = tan⁻¹ 0.3175

          θ₁ = 17.6º

          θ₂ = 67.0º

for these two angles the bullet hits the boat

Answer:

I do believe her actions were justified.

Explanation:

Due to the school charging extra fee from her father who makes a modest amount as a teacher. There was sum of money involved that could change how he lived and her.

I do not believe her actions where justified

She had a lot going for her. She could have skipped the hardship of helping grace and pass. She could have easily have gotten a good job with a degree and paid back all the debts owed. Alot of troubles could have been avoided just by doing her own thing.

Answer:

  μ = 0.66,    therefore if it compiesy with the regulations

Explanation:

Let's solve this exercise in part, let's start by finding with kinematics the acceleration of man

           y = v₀ t + ½ a t²

as it starts from rest the initial velocity is zero

          y = ½ a t²

          a = [tex]\frac{2y}{t^2}[/tex]

          a =\frac{2 \ 4.38}{1.21^2}  

          a = 6.46 m / s²

Now let's use Newton's second law,

Axis y

         N- W = 0

         N = W

         N = m g

X axis

on this axis the man exerts a backward force and by the law of action and reaction the floor exerts a forward force of the same magnitude, this forward force is the friction force.

         fr = m a

the friction force has an expression

          fr = my N

let's substitute

      μ mg = m a

      μ = a / g

let's calculate

     μ = 6.46 / 9.8

     μ = 0.66

therefore if you comply with the regulations

Answer:

I hear points of low volume sound and points of high volume of sound.

Explanation:

This is because, since the two sources of sound have the same frequency and are separated by a distance, d = 10 mm, there would be successive points of constructive and destructive interference.

Since their frequencies are similar, we should have beats of high and low frequency.

So, at points of low frequency, the amplitude of the wave is smallest and there is destructive interference. The frequency at this point is the difference between the frequencies from both speakers. Since the frequency from both speakers is 400 Hz, we have, f - f' = 400 Hz - 400 Hz = 0 Hz. So, the volume of the sound is low(zero) at these points.

Also, at points of high frequency, the amplitude of the wave is highest and there is constructive interference. The frequency at this point is the sum between the frequencies from both speakers. Since the frequency from both speakers is 400 Hz, we have, (f + f') = 400 Hz + 400 Hz = 800 Hz. So, the volume of the sound is high at these points.

So, as you wander around the room, I should hear points of high and low sound across the room.