which of the following is used to answer scientific questions?

A. Experiments

B. Intuition

C. Opinion polls

D. Imagination​

Answer:

75 cm/second.

Explanation:

Formula:

Walking speed = stride length / time per step

Walking speed = 90cm/time per step

                         = 90cm/1.2 seconds (a common estimate time per step)

                         = 75cm/second.

Answer:

Explanation:

Introduction:

As the world shifts towards renewable energy sources, the use of wind power is becoming increasingly popular. Wind power harnesses the power of the wind to generate electricity, and it has proven to be a reliable, cost-effective, and environmentally-friendly source of energy. In this report, we will discuss the benefits of wind power and how it can be used in our community.

Benefits of Wind Power:

Wind power has numerous benefits, including:

Clean and Environmentally-Friendly: Wind power generates electricity without producing harmful greenhouse gas emissions, air pollution, or toxic waste. It is a clean and sustainable energy source that helps reduce our carbon footprint and combat climate change.

Cost-Effective: Wind power is one of the most cost-effective renewable energy sources available today. Once a wind turbine is installed, the ongoing operating costs are relatively low, and the energy produced is essentially free.

Energy Security: Wind power provides energy security and independence. It reduces our dependence on foreign oil and other fossil fuels, which can be affected by geopolitical conflicts, price fluctuations, and supply disruptions.

Job Creation: Wind power creates jobs in the construction, maintenance, and manufacturing sectors. The growth of the wind power industry can provide economic benefits to our community and the country as a whole.

How Wind Power Works:

Wind power works by harnessing the kinetic energy of the wind and converting it into electrical energy. Wind turbines consist of a rotor, blades, a nacelle, and a tower. As the wind blows, it causes the rotor to spin, which in turn spins the blades. The blades are designed to capture the wind's energy and convert it into rotational energy. The rotational energy is then transferred to a generator in the nacelle, which converts it into electrical energy. The electricity is sent to a transformer, which increases the voltage and sends it to the power grid for distribution.

Using Wind Power in Our Community:

Our community has several options for using wind power, including:

Small-Scale Wind Turbines: Small-scale wind turbines can be installed on residential or commercial properties. They can generate enough electricity to power a home or business, and any excess energy can be sent back to the grid.

Large-Scale Wind Farms: Large-scale wind farms can be installed in rural areas, where there is ample wind and space. These wind farms can generate large amounts of electricity and provide energy to the grid, which can be distributed to our community.

Conclusion:

Wind power is a reliable, cost-effective, and environmentally-friendly source of energy that can provide numerous benefits to our community. By investing in wind power, we can reduce our carbon footprint, create jobs, and secure our energy future. It is a smart investment that will pay off for years to come.

Answer:

Resistance, R = 60 Ohms

Explanation:

Given the following data;

For the first heater;

Voltage, V = 120 V

Resistance, R = 15 Ohms

For the second heater;

Voltage, V = 240 V

To find the resistance in the second heater;

First of all, we would determine the power rating of the heaters using the formula below;

Power = voltage²/resistance

Power = 120²/15

Power = 14400/15

Power = 960 Watts

Next, we find the resistance in the second heater;

Power = V²/R

960 = 240²/R

Cross-multiplying, we have;

960R = 57600

R = 57600/960

R = 60 Ohms

In a DC generator, the generated electromotive force (emf) is directly proportional to the rotational speed of the generator's armature and the strength of the magnetic field within the generator.

This relationship is described by the equation for the generated emf in a DC generator:

Emf = Φ * N * A * Z / 60

Where:

Emf is the generated electromotive force (in volts),

Φ is the magnetic flux density (in Weber/meter^2\(meter^2\) or Tesla),

N is the number of turns in the armature winding,

A is the effective area of the armature coil (in square meters),

Z is the total number of armature conductors, and

60 is a constant representing the conversion from seconds to minutes.

From this equation, we can see that the generated emf is directly proportional to the magnetic flux density (Φ) and the product of the number of turns (N), effective area (A), and the total number of armature conductors (Z). This means that increasing any of these factors will result in a higher generated emf.

The magnetic flux density (Φ) can be increased by using stronger permanent magnets or increasing the strength of the field windings in the generator.

The number of turns (N) and the effective area (A) are design parameters and can be optimized for a specific generator. Increasing the number of turns or the effective area will result in a higher generated emf.

Similarly, the total number of armature conductors (Z) can be increased to enhance the generated emf.

By controlling and optimizing these factors, the generated emf in a DC generator can be increased, resulting in higher electrical output. However, it is important to note that there are practical limits to these factors based on the design and construction of the generator.

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The magnitude of the resultant vector to round the answer to the nearest tenth, we look at the digit in the hundredth's place. If this digit is 5 or greater, we round up. If it is less than 5, we round down.

In the study of physics, we use vectors to represent quantities that have both direction and magnitude. It is often the case that we want to add two or more vectors together to obtain a single vector that represents the net result of these additions. The process of adding two or more vectors together is known as vector addition.The magnitude of the resultant vector is the length of the line that represents it on a scale drawing.

When we add two or more vectors together, the resultant vector is the vector that represents the net result of these additions. To find the magnitude of the resultant vector, we use the Pythagorean theorem, which states that the square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides.

In the case of vector addition, the hypotenuse is the resultant vector, and the other two sides are the component vectors. If we have two vectors a and b, the magnitude of the resultant vector is given by the following equation:|R| = √(ax2 + bx2)where R is the resultant vector, a and b are the component vectors, and x is the angle between the vectors.

For example, if the answer is 12.345, we would round it to 12.3.

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The path travelled by a projectile is known as its trajectory. The distance at which the two objects pass each other is 16.9 m.

Any object which is thrown into space and the only force acting on it is the force of gravity. The motion of a projectile is known as the projectile motion.

The height covered by the projectile from ground is:

h = ut - 1/2 gt²

h = 5t - 1/2 × 9.8 × t²

h = 5t - 4.9t²   (1)

When projectile is thrown downward, u = 0

65 - h = 1/2 gt²

65 - (5t - 4.9t² ) = 4.9t²

65 = 5t

t = 65/5 = 13 s

h = 65t - 4.9t²

= 65 × 13 - 4.9 × 169

= 16.9 m

Thus the distance at which the two objects pass each other is  16.9 m.

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The answer is Motion

Answer:

A.Radio waves

Explanation:

Answer:

1,360 m

Explanation:

340 meters per second, and it was 4 seconds later.

340 * 4 is how to find teh distance where the lightning struck.

340 * 4 = 1,360 meters

(1) The acceleration of the car is determined as 17.42 m/s².

(2) The acceleration of the crate is determined as 8.89 m/s².

The acceleration of the car is calculated from the net force acting on the car.

∑F = ma

F - Ff = ma

F - μW = ma

where;

m = W/g

m = (9320)/(9.8)

m = 951.02 kg

2(9320) - 0.222(9320) = 951.02a

16,570.96 = 951.02a

a = 17.42 m/s²

F - μW = ma

F - μmg = ma

302 - 0.75(18.6 x 9.8) = 18.6a

165.29 = 18.6a

a = 8.89 m/s²

Thus, the acceleration of the car is determined as 17.42 m/s².

The acceleration of the crate is determined as 8.89 m/s².

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To solve this we must be knowing each and every concept related to velocity. Therefore, the amplitude and maximum velocity are 0.23 m and 2.75 m/s respectively.

V is the velocity measurement of an object's rate of motion and direction of motion. As a result, in order to calculate velocity using this definition, we must be familiar with both magnitude and direction.

For example, if an item travels west with 5 meters a second (m/s), its velocity to the west will be 5 m/s. The most frequent and simplest approach to determine velocity is using the formula shown below.

v = √(k / m) ×A

v = velocity of the mass

k= spring constant

m =mass of the object

A= amplitude of the oscillation.

substituting all the given values in the above equation, we get

2.3 m/s = √(200 N/m / 3.00 kg)×A

A = 2.3 m/s / √(200 N/m / 3.00 kg)

    = 0.23 m

v =√(200 N/m / 3.00 kg) ×0.23 m

 = 2.75 m/s

Therefore, the amplitude and maximum velocity are 0.23 m and 2.75 m/s respectively.

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Answer:  S =  850 km/h = 235.11 m/s

Explanation:

average speed  = total distance : total time elapsed

           distance = 3400 km

           total time = 4 hours

average speed = D : T =  3400 km : 4 h = 850 km/h

[ 850 km /h = 850 000 m : 3600 s = 236.11 m/s ]

Answer:

They are attracted to each other. Maybe a magnet. Like 99% sure.

Explanation:

Objects that are usually attracted to each other are magnets. When you release two magnets close to each other, with each pole opposite to the other, they move toward each other and stick. You can only take them apart by force.

The kinetic energy of the book after it is slids a distance of 2 meters will be 10 Joules.

The work-energy theorem states that "the work done on an object is the change in its kinetic energy".

Hence;

Kinetic energy = work done

Note that: work-done is expressed as:

Work done = f × d

Where f is force applied and d is distance traveled.

Given that:

Force applied f = 5 newton

Distance d = 2 meters

Work done = ?

Plug these values into the above formula and solve for the workdone.

Work done = f × d

Work done = 5N × 2m

Work done = 10Nm

Work done = 10 Joules

Therefore, the kinetic energy is 10 Joules.

Option B) 10 J is the correct answer.

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Answer: velocity

Explanation:

Answer:

ummm there is nothing attached :(

Explanation:

Answer:

U don't give a numbers

Plz ask again

Answer:

500 / 31.25 = 16

(1/2)^n = 1/16     where n is the number of elapsed half-lives

(1/2)^4 = 1/16     so the sample has gone thru 4 half-lives

43 min * 4 = 172 min = 2.87 hrs

Answer:

it should be tension for the space

Answer:

tension

Explanation:

I'm not sure if I'm right but if the example is a pulley a pulley applies tension to a belt or rope or chain to keep it tight

Answer:

Colorless light

Explanation:

An example is day light.

Answer:

proportionally smaller

Explanation:

Answer:

\(\boxed {\boxed {\sf 3.5 \ Newtons}}\)

Explanation:

Force is the product of mass (in kilograms) and acceleration (in meters per square second).

\(F=ma\)

The mass of the ball is 140 grams and the acceleration is 25 m/s². Convert grams to kilograms.

Substitute the values into the formula.

\(F= 0.14 \ kg * 25 \ m/s^2\)

Multiply.

\(F= 3.5 \ kg*m/s^2\)

\(F= 3.5 \ N\)

3.5 Newtons of force are required.

Answer:Magnetic fields from two sources add up as vectors at each point, so the strength of the field is not necessarily the sum of the strengths1. Magnetic fields are vectors, which means they have direction as well as size. Therefore, the sum of two magnetic fields is not simply the sum of their magnitudes2.

Explanation:

The distance and Displacement travelled by skier is 17m and 16 m

Distance is the length of the actual path taken by object.

Displacement is the shortest distance between the initial and final position.

The SI unit of both distance and displacements is meter (m).

In this case,

Distance = 32m - 65m + 16 m

                 = 17 m

Here ,

Displacement  = Initial position - Final position

= 32m -16m  = 16m

Hence , The distance and displacement of the skier are 17m and 16m.

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The ratio of the force between two charges in a vacuum to the force between two charges when a medium is placed between them is called relative permittivity

Relative permittivity has another term dielectric constant. The dielectric constant measures how well a material can store electrical energy in an electric field. Its equation is ε = ε₀ / εᵣ

ε₀ is the vacuum permittivity, and εᵣ is the relative permittivity or dielectric constant of the medium.

The dielectric constant is different depending on the material.

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