Maggie is a member of her school’s environmental club and is interested in recycling. She asks the question, “How does exposure to the environment affect recyclable plastics?”

What best describes why and how Maggie should change her question to make it a better scientific question?

The answer to the question leads to a testable hypothesis, so the question should be changed to prevent testing.
The question involves giving an opinion about recycling, so it should be changed to rely only on facts.
The focus of the question is too broad, so it should be narrowed to a single environmental factor.
The results are too uncertain, so the question should be changed to one that has a known outcome.

Answer:

NO.

Explanation:

METALLIC BOND IS ONLY IN METALS.

Since iron is a metal and carbon a non- metal, they cannot form a metallic bond.

Explanation:

R = [tex]\sqrt{(12.0)^{2} + (9.00)^{2}}[/tex] = 15 UNIDADES

Answer:

Final velocity (v) = 36 m/s

Distance traveled (s) = 2,160 m

Explanation:

Given:

Initial velocity (u) = 0

Acceleration (a) = 0.3 m/s

Time travel (t) = 2 minutes = 120 seconds

Find:

Final velocity (v) = ?

Distance traveled (s) = ?

Computation:

v = u + at

v = 0 + 0.3(120)

v = 0.3(120)

v = 36 m/s

Final velocity (v) = 36 m/s

Distance traveled (s) = ut + (1/2)at²

Distance traveled (s) = (0.5)(0.3 × 120 × 120)

Distance traveled (s) = 2,160 m

Answer:

There is no answer, since a closed-pipe resonator can NOT have a second harmonic. However, if you were to plug the pipe length and the speed of sound into the closed-pipe equation anyway you would get 49.56 as your fundamental frequency, which means that 99.13 would be your "plug and play" 2nd harmonic.

Explanation:

Answer:

K is the spring/elastic constant measured in Newton per metre square (N/m²)

Explanation:

E = ½Ke²

In the equation above,

E is the energy in Joules (J)

K is the elastic/spring constant in Newton per metre square (N/m²)

e is the extension in metre (m)

Answer:

In the equation Ee = ½ × k × e², "k" = spring constant

Explanation:

Answer: they will rise up because hydrogen is lighter in density and it's weight is lower when it's in the air

Explanation:

Answer:

hydrogen is less dense and its weight is also less than the air.

Explanation:

'''In a series circuit, the sum of the voltages consumed by each individual resistance is equal to the source voltage. Components connected in parallel are connected along multiple paths so that the current can split up; the same voltage is applied to each component.''

Answer:

Explanation:

Sounds travel faster in object having high density proportion or matter. This is because particles vibrates and causing the other particle near to as well vibrate. Hence, when sound is moving from a higher dense medium like Water, the rate of traveling is high compare to it moving in air with less dense.

Answer:

The net displacement is

[tex]R= \sqrt{A^2+B^2+2AB \cos \theta}[/tex]

[tex]=\sqrt{15^2+25^2+2AB \cos 30^\circ} \\\\=\sqrt{225+625+ \cos30^0} \\\\=38.7m[/tex]

Explanation:

Suppose that you walk 15 meters at 30 degrees as measured from the East. Then you walk another 25 meters at 60 degrees from the East what is your net displacement

Given data

A = 15 m

B = 25 m

Angle between the vectors A and B is θ = 30°

The net displacement is

[tex]R= \sqrt{A^2+B^2+2AB \cos \theta}[/tex]

[tex]=\sqrt{15^2+25^2+2AB \cos 30^\circ} \\\\=\sqrt{225+625+ \cos30^0} \\\\=38.7m[/tex]

Answer:

The hunter should aim directly at the perched monkey because the tranquilizer dart will fall away from the line sight at the same rate that the monkey falls from its perch.

Tan theta = 9 / 90 = .1      so theta = 5.71 deg

The time for the monkey to reach the ground is

t = (2 h / g)^1/2 = (18 / 9.8)^1/2 = 1.36 sec

So the horizontal speed of the dart must be at least

Vx = 90 m / 1.36 sec = 66.4 m/s

Vx = V cos theta

V = 66.4 m/s / cos 5.71 = 66.7 m/s

The angle of projection of the tranquilizer dart is 5.7⁰

The horizontal speed of the tranquilizer dart is 66.5 m/s

The given parameters;

The angle of projection of the tranquilizer dart is calculated as;

[tex]tan(\theta) = \frac{y}{x} \\\\tan(\theta) = \frac{9}{90} \\\\tan(\theta) = 0.1\\\\\theta = tan^{-1}(0.1)\\\\\theta = 5.71 ^0[/tex]

The speed of the tranquilizer dart is calculated as;

X = v₀ₓt

where;

t is the time to reach maximum height

X is the horizontal displacement = 90 m

The time to reach maximum height is calculated as;

[tex]h = v_0_yt + \frac{1}{2} gt^2\\\\h = 0 + \frac{1}{2} gt^2\\\\h = \frac{1}{2} gt^2\\\\t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2\times 9}{9.8} } \\\\t = 1.36 \ s[/tex]

The horizontal speed of the tranquilizer dart is calculated as;

[tex]X = v_0cos(\theta) \times t\\\\90 = v_0\times cos(5.71) \times 1.36\\\\90 = 1.353 v_0\\\\v_0= \frac{90}{1.353} \\\\v_0 = 66.5 \ m/s[/tex]

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Answer:

a) Shadow distance

10 cm in front of the mirror.

b) Zoom in the shadow

The shadow formed is the same height as the object and is placed also at the centre of curvature of the mirror as shown in the attached image to this solution.

c) The nature of the shadow

The shadow formed is real, inverted, same size as the object and formed at the centre of curvature.

Explanation:

English Translation

Objects as high as 3 cm are placed at a distance of 10 cm in front of a concave mirror with 10 cm curvature. Determine:

a) Shadow distance

b) Zoom in the shadow

c) The nature of the shadow

Solution

The mirror equation is given as

(1/f) = (1/v) + (1/u)

f = focal length of the mirror = (radius of curvature)/2 = 10/2 = 5 cm

v = image distance = ?

u = object distance = 10 cm

We can then calculate the shadow' s distance from the mirror thus

(1/5) = (1/v) + (1/10)

(1/v) = 0.2 - 0.1 = 0.1

v = (1/0.1) = 10 cm

b) Zoom in the shadow

Since the object is placed at the centre of curvature, as shown in the attached image, the image is formed at a point of intersection of rays. The image formed is the same height as the object and is placed also at the centre of curvature of the mirror.

c) The nature of the shadow

Since the mirror is a concave mirror, the image is real and formed in front of the mirror. The image is also inverted and formed at the centre of curvature of the mirror.

Hope this Helps!!!

Jess wants to make her house more energy efficient. Insulating her loft, which will cost £460 and save £25 per year, is better long-term option. Therefore, option B is correct.

In order to accomplish work and to produce heat and light, energy must be transferred to a body or to a physical system. Energy is the quantitative attribute that does this. Energy is a preserved resource; according to the rule of conservation of energy, energy can only be transformed from one form to another and cannot be created or destroyed.

Computers, vehicles, communications, state-of-the-art medical technology, and many other things are all powered by energy. The demand for dependable and economical energy is especially pressing for emerging countries. It may enhance things or perhaps save lives.

A turbine generator set transforms mechanical energy into electrical energy to produce electricity. Natural gas, coal, nuclear fission, biomass, petroleum, geothermal, and solar thermal are examples of energy sources where the heat generated is used to produce steam.

Thus, option B is correct.

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Answer:

A. Sliding friction

Explanation:

Sliding friction is weaker than static friction

Answer:

Rolling Friction

Explanation:

I know this because the definition of rolling friction is : type of friction that happens when one body rolls over another

Answer:

F = 0.32 N

Explanation:

GIVEN:

Mass = m =  200 g = 0.2 kg

Distance = S = 200 cm = 2 m

Time = t = 5 s

Initial velocity = U = 0 m/s

REQUIRED

Force = F = ?

SOLUTION

Using Second Equation of Motion,

S = Ut + 1/2 at²

2 = (0)(5) + 1/2 a(5)²

2 = 25/2 a

a = 4/25

a = 0.16 m/s²

So,

Acceleration = a = 0.16 m/s²

Now Using Equation from Newtons Second Law of Motion

F = ma

F = (2)(0.16)

F = 0.32 N

Explanation:

K = 5kg[tex](2 m/s)^{2}[/tex]/2 = 10 J

Answer:

a_max = 50 cm/s^2

Explanation:

To find the magnitude of the maximum acceleration of the particle, you take into account the equation of motion in a simple harmonic motion:

[tex]x=Acos(\omega t)[/tex]

ω: angular velocity = 10 rad/s

A: amplitude = 5 cm

The acceleration is given by:

[tex]a=\omega^2 x[/tex]

and the maximum acceleration is obtained when the cosine function is maximum, that is, when cos(wt) = 1. Then, you have:

[tex]a_{max}=\omega^2 x_{max}=\omega^2A[/tex]

Then, you replace the values of w and A in order to calculate a_max:

[tex]a_{max}=(10rad/s)^2(5cm)=50\frac{cm}{s^2}[/tex]

hence, the maximum acceleration is 50 cm/s^2

Answer:

A light ray is a line (straight or curved) that is perpendicular to the light's wavefronts

Explanation:

Have a great day.

Answer:

When an object falls, its gravitational potential energy is changed to kinetic energy. ... Gravitational potential energy for a mass m at height h near the surface of the Earth is mgh more than the potential energy would be at height 0. (It's up to you where you choose height 0.)

Explanation:

Answer:

Qwertyujiknb vcdxrftyhbvcdxrft6y7uij

Explanation:

Answer:

B

Explanation:

One positive charger and one negative charger

Answer:

80 Percent

Explanation:

E=energy output/energy input×100

E=8000/10000×100

E=0.8×100

E=80 percent.

Mark brianliest if my answer suit your question

If the machine put, in 8000 J, and the user puts 10,000 J of work then the efficiency of the machine will be equal to 80%.

Work is a physics term used to describe the transfer of energy that takes place when an object changes above a distance because of an external force, at least some of which is given in the vector of the dislocation. The element of the force acting all along the path multiplied by the length of the path can be used to calculate work if the force is constant.

Mathematically, this idea is expressed as W = fd, where W is the effort and f is the force multiplied by d, the distance. Work is completed whenever the force is applied at an angle with about the displacement.

As per the data provided in the question,

Total input energy = 10,000 J

Total output energy = 8,000 J

Then, the efficiency (η) of the machine will be,

η = (output energy/input energy) × 100

η = 8000/10000 × 100

η = 80%.

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The boat has to pull with MORE force. Don't forget about the force of friction with the water, pulling the skier in the backwards direction. The force that accelerates him is the NET force ... boat force minus water resistance. So the boat force has to be greater than the net accelerating force.

Answer:

Yes, in case of uniform velocity

Explanation:

This is the case of uniform velocity. If a body covers equal displacement in equal intervals of time, then the velocity of a body is said to be ‘Uniform Velocity’. It meas that the velocity of a body remains constant during the motion and it does not change.

Since, acceleration is defined as the rate of change of velocity.

Therefore, if there is no change in velocity or in other words the change in velocity is zero, then the acceleration is also zero.

a = ΔV/t = 0/t

a = 0 m/s²

So, the acceleration of the body is 0 m/s², but it has a uniform velocity

Hence, it is possible for an object that, object with zero acceleration have velocity, which is the case case of uniform velocity.

Answer:

2.331

Explanation:

It just the change of Energy from potential (PE) to kinetic (KE)

PE on A = PE on B + KE on B + friction works (Wf)

mg(ha) = mg(hb) + ½mv² + Wf

35 * 9.8 * 1.5 = 35 * 9.8 * 0.8 + ½ * 35 * v² + 145

514.5 = 274.4 + 17.5v² + 145

514.5 - 274.4 - 145 = 17.5v²

17v² = 95.1

v² = 5.434

v =√5.434 = 2.331 m/s

Answer:

0.333

Explanation:

Weight of the sinker in water = 25gf

Weight of cork in air and sinker in water = 25gf + 2.5gf

= 27.5gf

Weight of the cork and sinker in water = 20gf

Loss of weight of cork in water = 27.5- 20 = 7.5gf

Rd of cork = weight of cork in air/ loss of weight of cork in water

= 2.5/7.5

= 1/3

= 0.333

Hence the Relative density of the cork is 0.333

Answer: - 452.088joule

Explanation:

Given the following :

Mass of water = 12g

Change in temperature(Dt) = (11 - 20)°C = - 9°C

Specific heats capacity of water(c) = 4.186j/g°C

Q = mcDt

Where Q = quantity of heat

Q = 12g × 4.186j/g°C × - 9°C

Q = - 452.088joule

Inertia is the same thing as mass, more or less. Inertia is the tendency of the object to want to stay in place if at rest, or the object's tendency to stay in motion if a force is applied to it. A train's inertia is massive because it takes a lot of force to move such a large mass, or to slow it down. This is in comparison to the other objects (rubber ball, stone, bike, and the coins).

Answer:

Inertia is the measure of the mass of the body. The greater is the mass of the body; the

greater is its inertia and vice-versa.

(a) Mass of a stone is more than the mass of a rubber ball for the same size. Hence, inertia of

the stone is greater than that of a rubber ball.

(b) Mass of a train is more than the mass of a bicycle. Hence, inertia of the train is greater

than that of the bicycle.

(c) Mass of a five rupee coin is more than that of a one-rupee coin. Hence, inertia of the five

rupee coin is greater than that of the one-rupee coin.

A cord is wrapped around the outer surface of the 8-kg disk. If a force of F = (1⁄4θ²) N, where θ is in radians, is applied to the cord, determine the disk’s angular acceleration when it has turned 5 revolutions. The disc has an initial angular velocity [tex]\omega _o = 1 \ rad/s[/tex] and radius from the center of the disc = 300 mm

Answer:

the angular acceleration = 205.706 rad/sec²

Explanation:

GIVEN THAT:

The disc mass = 8 kg

Force = [tex]\dfrac{1}{4} \ \ \theta ^2* N[/tex]

We are told that the given θ is in radians; Therefore; the when it has turned 5 revolutions; we have the θ to be:

[tex]\theta = 5 rev * (\dfrac{2 \ \pi * rad}{1 rev}) \\ \\ \theta = 10 \ \pi \ rad[/tex]

Also;

the initial angular velocity [tex]\omega _o = 1 \ rad/s[/tex]

radius from the center of the disc = 300 mm = 0.3 m

Thus; the mass moment about the Inertia can be determined via the following expression;

[tex]I_o = \dfrac{1}{2}*m*r^2[/tex]

[tex]I_o = \dfrac{1}{2}*8*0.3^2[/tex]

[tex]I_o = 0.36 \ kg/m^3[/tex]

Now to calculate the angular acceleration; we equate the sum of the moments acting on the Inertia;

SO:

[tex]\sum M_o = I_o \alpha[/tex]

[tex]F*0.3 = 0.36* \alpha[/tex]

[tex]\dfrac{1}{2}* \theta^2 *0.3 = 0.36* \alpha[/tex]

[tex]\alpha = 0.20836 \ \theta^2 \ rad/sec^2[/tex]

[tex]\alpha = 0.20836 \ (10 \ \pi )^2 \ rad/sec^2[/tex]

[tex]\alpha = 205.706 \ rad/sec^2[/tex]

Hence; the angular acceleration = 205.706 rad/sec²

Answer:

Explanation:

The quantity of heat required to raise the temperature of water to 100 degrees is expressed as

[tex]Q= mc(T2-T1)[/tex]

Given data

mass of water = 5kg

initial temperature T1= 20 °C

final temperature T2= 100 °C

Specific heat capacity of water=  4 200 J/Kg °C

[tex]Q= 5* 4 200(100-20)\\Q= 21000(80)\\Q= 1680000\\Q= 1680kJ[/tex]