On her camping trip, Penelope was in charge of collecting firewood. The firewood she found had a mass of 120 g and a volume of 480 cm3. What is the density of the firewood? Explain the steps you took to solve this problem.

Answer:

Their measured results are closer to the exact or true value. Hence, their measured value is considered to be more accurate.

Explanation:

Considering the situation described above, the accuracy of a measured value depicts how closely a measured value is to the accurate value.

Hence, since the students' measured values have very low percent differences, it shows the similarity of computations or estimates to the actual values, which in turn offers a smaller measurement error.

Therefore, their measured results are closer to the exact or true value, which implies that their measured value is considered to be more accurate.

Answer: I think the ans is A but I’m not sure.

Can someone check it and tell me I would like to know

Answer:

I think it is of science is it true na i knew it bro dont take tension

Nearly four hours every day, doing little to no physical activity.

Answer:

i think its c

Explanation:

trust me

Answer:

 [tex]\frac{t_{air}}{t_{vaccum}}[/tex] = 1.00029

Explanation:

The refractive index is defined

         n = c / v

         v = c / n

the speed of light per se wave is constant, so we can use the relations of uniform motion

         v = x / t

         t = x / v

we substitute

         t = x n / c

let's calculate the time

vacuum

        t₁ = 1000 1/3 10⁸

        t₁ = 3.333333 10⁻⁶ s

air

        t₂ = 1000 1.00029 / 3 10⁸

        t2 = 3.3343 10⁻⁶ s

the relationship between these times is

       t₂ / t₁ = 3.3343 / 3.3333333

       t₂ / t₁ = 1.00029

Answer:

pha của dao động là hàm bậc nhất của thời gian.

Answer:

杰恩斯克克斯克奇沃伊斯克克斯克什德布德克什恩克恩德恩克恩茨克杰兹姆克斯恩斯姆斯姆德恩德姆德武伊乔奥斯克斯杰德布德赫德夫赫富伊什杰吉迪赫德赫夫赫德

Answer:

Scientists learn more about the natural world through investigation by identifying a problem, researching related information, designing and conducting an investigation, analyzing the results, evaluating the conclusion, and communicating the findings. Engineers follow similar steps when creating new products or solutions through technological design. The four stages of technological design include identifying a need, designing and implementing a solution, and evaluating the solution.

Answer:

T₁ = 232.5 ºC

Explanation:

For this exercise let's start by finding the value of the resistance for the two currents, using Ohm's law

           V = i R

            R = V / i

i₀ = 1.28 A

            R₀ = 120 / 1.28

            R₀ = 93.75 ohm

i₁ = 1.229 A

             R₁ = 120 / 1.229

             R₁ = 97.64 or

Resistance in a metal is linear with temperature

            ΔR = α R₀ ΔT

where the coefficient of thermal expansion for Nichrome is α=0.0002 C⁻¹

            ΔT = [tex]\frac{\Delta R}{\alpha R_o}[/tex]

            ΔT = [tex]\frac{97.64 \ -93.75}{ 0.00020 \ 93.75}[/tex]

            ΔT = 2,075 10² C

            ΔT = T₁-T₀ = 2,075 10²

            T₁ = T₀ + 207.5

             T₁ = 25+ 207.5

             T₁ = 232.5 ºC

Answer: [tex]377.3\ kPa[/tex]

Explanation:

Given

Water column height [tex]h=25\ cm[/tex]

After oil is poured, the total height becomes [tex]h'=40\ cm[/tex]

Pressure at the bottom will be the sum due to the water and oil column

Suppose the density of the oil is [tex]\rho=900\ kg/m^3[/tex]

Pressure at the bottom

[tex]\Rightarrow P=10^3\times g\times 25+900\times g\times 15\\\Rightarrow P=100g[250+135]\\\Rightarrow P=3773\times 100\ Pa\\\Rightarrow P=377.3\ kPa[/tex]

Answer:

the force exerted by the umbrella against the drops is the same in both cases  

Explanation:

In this exercise the total mass of the raindrops and the hail are equal, therefore the momentum that these drops create is

raindrops       I₁ = ∫ F dt

hail                 I₂ = ∫ F dt

since the mass and the velocity is the same the force is the weight of the drops

                  F = mg

whereby the impulse is

                 I₁ = mg t

                 I₂ = mg t

we can see that the impulses generated by hail and raindrops are equal, therefore the force exerted by the umbrella against the drops is the same in both cases  

Explanation:

Given that,

Two resistors 4.5 Ω and 2.3 Ω .

Potential difference = 30 V

When they are in series, the current through each resistor remains the same. First find the equivalent resistance.

R' = 4.5 + 2.3

= 6.8 Ω

Current,

[tex]I=\dfrac{V}{R'}\\\\I=\dfrac{30}{6.8}\\\\=4.41\ A[/tex]

So, the current through both lightbulb is the same i.e. 4.41 A.

When they are in parallel, the current divides.

Current flowing in 4.5 resistor,

[tex]I_1=\dfrac{V}{R_1}\\\\=\dfrac{30}{4.5}\\\\I_1=6.7\ A[/tex]

Current flowing in 2.3 ohm resistor,

[tex]I_2=\dfrac{V}{R_2}\\\\=\dfrac{30}{2.3}\\\\I_2=13.04[/tex]

In parallel combination, are brighter than bulbs in series.

Answer:

Option (2) is correct.

The energy density of an electromagnetic wave is equally divided between the magnetic and electric fields.

Explanation:

An electromagnetic waves are the waves which are produced when the oscillating electric and magnetic field are interact each other perpendicular to each other. The direction of propagation of electro magnetic waves is perpendicular to each electric and magnetic fields.

The energy associated with the electromagnetic waves is equally distributed in form of electric and magnetic fields.

So, the correct option is (2).

The energy density is equally distributed among the magnetic field and electric field. Hence, option (2) is correct.

The given problem is based on the concept and fundamentals of electromagnetic waves.  The waves created as a result of vibrations between an electric field and a magnetic field is known as Electromagnetic waves.

In other words, an electromagnetic waves are the waves which are produced when the oscillating electric and magnetic field are interact each other perpendicular to each other. The direction of propagation of electro magnetic waves is perpendicular to each electric and magnetic fields.

Also, the energy associated with the electromagnetic waves is equally distributed in form of electric and magnetic fields. So, the energy density of an electromagnetic wave is equally divided between the magnetic and electric fields.

Thus, we can conclude that the energy density is equally distributed among the magnetic field and electric field.

Learn more about the electromagnetic waves here:

https://brainly.com/question/25559554

Answer:

The viscosity is 1.30 x 10^-3 deca poise.

Explanation:

Volume per minute, V = 10^-5 m^3

Volume per second, V = 1.67 x 10^-7 m^3

density, d = 800 kg/m^3

radius, r = 0.05 cm

Length, L = 0.5 m

Height, h = 60 cm

Pressure, P = h d g = 0.6 x 800 x 9.8 = 4704 Pa

Use the formula  of rate of flow

[tex]V = \frac{\pi p r^4}{8\eta L}\\\\1.67\times 10^{-7}\times8\times \eta\times 0.5 = 3.14\times 4707\times (0.05\times 10^{-2})^4\\\\\eta = 1.38\times 10^{-3} deca poise[/tex]

Answer:

Explanation:

The fish will have horizontal velocity of 2.6 m/s which is also the velocity of eagle. Additionally , he will have vertical velocity due to fall under gravity .

v² = u² + 2 g H .

v² = 0  + 2 x 9.8 x 4.7 m

= 92.12

v = 9.6 m /s

The fish's final velocity will have two components

vertical component = 9.6 m/s downwards

Horizontal component = 2.6 m /s  .

Resultant velocity = √ ( 9.6² + 2.6² )

= √ ( 92.16 + 6.76 )

= 9.9 m /s

Answer:

The speed of fish at the time of hitting the surface is 9.95 m/s.

Explanation:

Horizontal speed, u = 2.6 m/s

height, h = 4.7 m

Let the vertical velocity at the time of hitting to water is v.

Use third equation of motion

[tex]v^2 = u^2 - 2 gh \\\\v^2 = 0 + 2 \times 9.8\times 4.7\\\\v = 9.6 m/s[/tex]

The net velocity with which the fish strikes to the water is

[tex]v' = \sqrt{9.6^2 + 2.6^2 }\\\\v' = 9.95 m/s[/tex]

Answer:

a.work done by man A is zero

D is best option

Explanation:

D none of them because as we know that to do work some distance should be cover with some load as both picture they are covering some distance with carrying some load so A and B option are absolutely wrong and remaining C they are not doing same amount of work because distance cover by them and load carrying by them is different so how can work be same so D is best option none of A B C is correct answer

Calculate force of each car:

P1 = 900 kg x 12m/s = 10,800

P2= 600 x 24 = 14,400

Degree of travel = arctan(14,300/10800)

Degree of travel = 53.1 N of E

Answer:

The correct answer is - low pitch

Explanation:

Now for the case it is mentioned that the tube closed on one end frequency is:

f = v/2l

Where,

l = length of the tube

v = velocity of longitudinal wave of gas filled in the tube

if frequency increases then pitch will be increase as well as pitch depends on frequency.

Now increase with the temperature the density of the gas decreases and velocity v is inversely proportional to density of gas so velocity increases. So if there is an increase in frequency so pitch also increases.

As the temperature inside the house is at 750 F more than outsideat 450 Fso pitch is more inside and the pitch is low outside.

Answer:

c). It wouldn't change.

Explanation:

[tex]{ \bf{F = \frac{ \ \gamma _{o}NI }{l} }}[/tex]

Explanation:

They believe that vortexes occur at the planet's north pole because of atmospheric flows deep within the gas giant, and that these vortexes pinch an intense horizontal jet near the equator—which is what warps the storm into a hexagon

Answer:

u can ask it to the person who give ot to u i dont no

Answer:

b

Explanation:

Answer:

(a) The area vector is 0.00503 m² at 30⁰ from the magnetic field

(b) The induced emf is 12.58 V

Explanation:

Given;

angle between the magnetic field and the plane of the circular coil, = 30⁰

number of turns of the coil, N = 1000

radius of the coil, r = 4 cm = 0.04 m

change in the magnetic field with time, dB/dt = 5 T/s

(a) The area vector is calculated as;

A = πr²

A = π x (0.04)²

A = 0.00503 m²

The area vector is 0.00503 m² at 30⁰ from the magnetic field.

(b) The induced emf is calculated as;

[tex]emf = N\frac{\Delta \phi}{\Delta t} \\\\where;\\\\\phi = BAcos \theta\\\\emf = N\times \frac{dB}{dt} \times Acos (\theta)\\\\where;\\\\\theta \ is \ the \ angle \ between \ a \ perpendicular \ vector \ to \ the \ area\\ and\ the \ magnetic\ field\\\\\theta = 90 - 30 = 60^0\\\\emf = N\times \frac{dB}{dt} \times Acos (\theta)\\\\emf = (1000) \times (5 )\times (0.00503) \times cos (60)\\\\emf = 12.58 \ V[/tex]

Answer:

 F = - k (x-xo) a graph of the weight or applied force against the elongation obtaining a line already proves Hooke's law.

Explanation:

The student wants to prove hooke's law which has the form

          F = - k (x-xo)

To do this we hang the spring in a vertical position and mark the equilibrium position on a tape measure, to simplify the calculations we can make this point zero by placing our reference system in this position.

Now for a series of known masses let's get them one by one and measure the spring elongation, building a table of weight vs elongation,

we must be careful when hanging the weights so as not to create oscillations in the spring

we look for the mass of each weight

         W = mg

          m = W / g

and we write them in a new column, we make a graph of the weight or applied force against the elongation and it should give a straight line; the slope of this line is sought, which is the spring constant.

The fact of obtaining a line already proves Hooke's law.

Answer:

76969.29 W

Explanation:

Applying,

P = F×v............. Equation 1

Where P = Power, F = force, v = velocity

But,

F = ma.......... Equation 2

Where m = mass, a = acceleration

Also,

a = (v-u)/t......... Equation 3

Given: u = 0 m/s ( from rest), v = 12.87 m/s, t = 3.47 s

Substitute these values into equation 3

a = (12.87-0)/3.47

a = 3.71 m/s²

Also Given: m = 1612 kg

Substitute into equation 2

F = 1612(3.71)

F = 5980.52 N.

Finally,

Substitute into equation 1

P = 5980.52×12.87

P = 76969.29 W

Explanation:

Answer:

I think it's 9 but edge says it's not

Explanation:

it should be 3√9^2

Answer:

change the magnetic field more quickly.

Explanation:

An electric field is defined as a region or an field which surrounds an [tex]\text{electrically-charged particle}[/tex] where it exerts force on all other particles that are charged present in the field or the region.

A magnetic field is defined as the physical field created by a magnet or by a moving charge which creates a force on another moving charge.

The strength of the induced electric field depends on the magnetic field. The change in the magnetic flux induces the electric field. As a result, for creating a larger induced electric field one have change the magnetic field quickly.

Answer:

Current = 0.000294 A

Explanation:

Below is the given values:

Given the charge = 9.00 C

Time = 8.50 h

Use the below formula to find the current:

Current = Q / t

Now plug the values:

Current = 9 / (8.5 x 3600)

Current = 0.000294 A

This question is incomplete, the complete question is;

A 70-turn coil has a diameter of 11 cm. Find the magnitude of the emf induced in the coil (in V) if it is placed in a spatially uniform magnetic field of magnitude 0.70 T so that the face of the coil makes the following angles with the magnetic field, and the magnetic field is reduced to zero uniformly in 0.2 s. a) θ = 30° V b) θ = 60° V c) θ = 90° V

Answer:

the magnitude of the emf induced in the coil are;

a)- For θ = 30°, e = 1.16 V

b)- For θ = 60°, e = 2.01 V

c)- For θ = 90°, e = 2.33 V

Explanation:

Given the data in the question;

number of turns N = 70

Diameter of coil D = 11 cm

Radius r = D/2 = 11/2 = 5.5 cm = 0.055 m

magnitude of magnetic ΔB = 0.7T

Δt = 0.2 seconds

Now,

a)

For θ = 30°,

Angle of with area of vector θ' = 90° - 30° = 60°

so

emf  e = N( Δ∅ / Δt ) = N( ΔBAcosθ  / Δt )

hence

e =  NAcosθ'(ΔB / Δt )

where A is area ( πr² )

so we substitute

e =  70 × πr² × cos(60°) × ( 0.7 / 0.2 )

e =  70 × π(0.055)² × cos(60°) × ( 0.7 / 0.2 )

e = 1.16 V

b)

For θ = 60°,

Angle of with area of vector θ' = 90° - 60° = 30°

so

e =  NAcosθ'(ΔB / Δt )

we substitute

e =  70 × πr² × cos(30°) × ( 0.7 / 0.2 )

e =  70 × π(0.055)² × cos(30°) × ( 0.7 / 0.2 )

e = 2.01 V

c)

For θ = 90°,

Angle of with area of vector θ' = 90° - 90° = 0°

so

e =  NAcosθ'(ΔB / Δt )

we substitute

e =  70 × πr² × cos(0°) × ( 0.7 / 0.2 )

e =  70 × π(0.055)² × cos(30°) × ( 0.7 / 0.2 )

e = 2.33 V

Therefore, the magnitude of the emf induced in the coil are;

a)- For θ = 30°, e = 1.16 V

b)- For θ = 60°, e = 2.01 V

c)- For θ = 90°, e = 2.33 V

Answer:

Remember that as the temperature of an object increases, the kinetic energy of the particles inside it also increases.

So, if the temperature of a wire increases, the kinetic energy of the particles inside increases. Then when the electrons try to flow through the wire, the probability of a collision is increased (then the resistance increases). Thus, if the filament goes from red-hot to white-hot (so the temperature of the wire increases) we can conclude that the resistance that the current experiences also increases.

So no, we can not expect the resistance of the light bulb to remain constant as the filament goes from red-hot to white-hot.