a man hikes 6.6 km north along a straight path with an average velocity of 4.2 km/h to the north. he rest at a bench for 15 min. then, he hikes 3.8 km birth with an average velocity of 5.1 km/h to the north. how long does it take the total hike to last

Answer:

2) center mass

3) when work is done by a system, energy is released

Explanation:

Answer:

(a)  0.273 A

(b) 4.368 V

(c) 1.638 V

Explanation:

From the question,

(a) Applying ohm's law

V = IR'...................... Equation 1

Where V = Voltage of the battery, I = Current in each of the resistor, R' = Total resistance of the combined resistors

Since the Two resisstors are connected in series,

(i) The same current flows through both resistors

(ii) The total resistor (R') = R₁+R₂

Therefore,

V = (R₁+R₂)I

Make I the subject of the equation

I = V/(R₁+R₂)................. Equation 2

Given: V = 6 V, R₁ = 16 Ω, R₂ = 6 Ω

Substitute into equation 2

I = 6/(16+6)

I = 6/22

I = 0.273 A

(b) The potential difference across the first resisto

V₁ = IR₁...................... Equation 3

Given: I = 0.273 A, R₁ = 16 Ω

Substitute these values into equation 3

V₁ = 0.273(16)

V₁ = 4.368 V

(c) The Potential difference across the second resistor is

V₂ = IR₂.................... Equation 4

V₂ = 0.273×6

V₂ = 1.638 V

Answer:

Seconds

Explanation:

Hope it helps you in your learning process.

The rate of flow of charge (per second) through a conductor is called electric current.

S. I unit of electric current is Ampere (named after French Physicist Andre Marie Ampere)

Answer:

A: Alpha decay.

Explanation:

The transmutation of ²³⁸U is a nuclear reaction that yields ²³⁴Th and an alpha particle.

Now, Alpha decay is a radioactive decay whereby an atomic nucleus emits an alpha particle which then changes into an atom with a mass number that is decreased by four and atomic number decreased by 2.

In this case, mass number is reduced from 238 to 234. Thus, it's an alpha decay.

Answer:

11.25J

Explanation:

15=(output/75)x100

output =(75x15)/100=11.25J

Answer:

271.095 m

Explanation:

✓ Let speed of sound in air that was given as (343 m/s) be represented as (Vi)

✓( speed of sound in concrete that was given as (3000 m/s ) be debited as (Vc)

✓ Let the distance travelled by the sound = s

✓duration of Time that exist between heard of sounds = 0.70s

But we know that

Time = (Distance / Speed)

✓Time it takes the sound to travel through air= s/vi = s/343

✓Time it takes the sound to travel through concrete= s/vc = s/3000

✓ (s/343) - (s/3000) = 0.70

Finding LCM and simplify

[(3000s - 343s)]/1029000 = 0.70

2657s /1029000 = 0.70

Making " s" subject of the formula

s= (1029000 × 0.70)/2657

s=720300/ 2657

s= 271.095 m

Hence, The impact took place at a distance of 271.095 m away from the person.

Answer:

   f = q

Explanation:

In the attachment we can see a diagram of the parallel rays.

The dotted line represents the normal to the mirror surface

These rays when reflected using the constructor equation

        [tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}[/tex]

where p and q are the distance to the object and the image respectively.

Since the rays are parallel P = inf

          1 / f = 1 / inf + 1 / q

          f = q

this means that all the rays focus on one focal point.

Answer:

The amount of energy carried by a wave is related to the amplitude of the wave

Explanation:

A high energy wave is characterized by a high amplitude; a low energy wave is characterized by a low amplitude.  The energy imparted to a pulse will only affect the amplitude of that pulse.

Hope this helped!!!

Answer:

Hope this helps!  can I have brainliest im trying to level up.

Explanation:

Bumper cars are a great place to see Sir Isaac Newton’s three laws of motion in action. Here’s how:

Newton’s First Law: Every object in motion continues in motion and every object at rest continues to be at rest unless an outside force acts upon it.

This is because all objects have inertia – the property of matter that resists changes to the object’s motion.

Newton found that if a ball is sitting on a table, it will stay sitting there because that is what it ‘wants’ to do.

If the ball is set in motion, it will keep traveling in a straight path because, again, that is what it ‘wants’ to do.

An object in motion will not stop, slow down, or change its direction unless an outside force acts on it (such as gravity, friction, and air resistance).

When you are riding in a bumper car and end up in a collision with another bumper car, you feel a jolt. This is because your body’s inertia wants it to keep traveling in the direction it was moving with the car even though your bumper car has now suddenly stopped.

Newton’s Second Law: The greater the mass of an object, the harder it is to change its speed.

(More force is needed to move it.)

You already know this law and practice it in your everyday life. Something that is small, such as a pebble, is much easier to pick up and throw than something that is large and heavy, such as a boulder.

When riding in the bumper cars, you may have noticed that people who weigh less tend to get pushed around more than people who weigh more.

The more mass (weight) an object has, the more force it takes to move it.

And since all the bumper cars usually have the same top velocity, the cars carrying more mass will never travel as far as the cars carrying less mass after a collision.

Newton’s Third Law: For every action, there is an equal and opposite reaction.

If two bumper cars traveling at the same speed and carrying the same amount of weight run into each other, they will bounce off and move an equal distance away from each other.

And based on the second law, if there is a difference in the amount of weight being carried in the two cars, the car with less weight will travel farther away from the point of impact than the car carrying more weight.

Answer:

Atoms

Explanation:

Atoms make up everything

Answer:

32km per hour

Explanation:

Explanation:

In first case v = a t

==> a t = 40 km p h

Now distance covered S1 + S2 + S3

S1 = 1/2 a t^2 and S3 = 1/2 a t^2

But S2 = 3t * 40 = 120 t km

Hence total distance = at^2 + 120 t

Time taken (total) = t + 3t + t = 5 t

Hence average speed = at^2 + 120 t / 5 t

Cancelling t we have at + 120 / 5 = 40 + 120 / 5 = 160/5 = 32 km per hour

Answer:

C. an infinite distance from the lens

Explanation:

There are five distinct cases of image formation in a convex lens depending upon the position of an object:

1. When the object is placed at an infinite distance from the lens, its real image is formed at the focal point.

2. When the object is placed before the center of curvature of the lens, its real image is formed between the center of curvature and the focal point.

3. When the object is placed at the center of curvature of the lens, its real image is formed at the center of curvature.

4. When the object is placed between the center of curvature and the focal length of the lens, its real image is formed behind the center of curvature.

5. When the object is placed at the focal point of the lens, its virtual image is formed at infinity.

Hence, from point 5 the answer is:

C. an infinite distance from the lens

62.5 m/s

Explanation:

The speed of a wave is 40 m/s. If the wavelength is 80 centimeters, what is the frequency of the wave ?

Velocity (V) = 40 m/s

Wavelength [tex] (\lambda) [/tex] = 80 cm = 0.8 m

The frequency (F) of the wave.

We know,

[tex] \bf V \: = \: F \: × \: \lambda [/tex]

40 = F × 0.8

F = [tex] \frac{40}{0.8} [/tex]

F = 50

Answer:

A<L BO DI ED

Explanation:

Answer: I=0.52 A

Explanation:

Given

Voltage is [tex]2.5\ V[/tex]

Resistance [tex]R=4.8\ \Omega[/tex]

Current is given by

[tex]I=\dfrac{V}{R}[/tex]

[tex]\Rightarrow I=\dfrac{2.5}{4.8}=0.52\ A[/tex]

Answer:

0.9m/s

?

Explanation:

The process by which rock minerals are changed by natural processes into new substances is known as chemical weathering. Option A is correct.

The breakdown or dissolution of rocks and minerals on the Earth's surface is referred to as weathering.

Weathering is the erosion or disintegration of rocks, building materials, etc., induced by chemical interactions dissolved in it rather than by mechanical processes.

Water, ice, acids, salts, plants, animals, and temperature variations are all weathering agents.

Chemical weathering is the process by which rock minerals are transformed into new compounds by natural processes.

Hence, option A is correct.

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Answer:

$1.26

Explanation:

Power =energy/ time

energy =powerxtime

energy =50x31x24=37200

=37.2kwh

1kwh =3.39

37.2kwh=3.39x37.2=126.108cent

=$1.26

The moment of inertia of Pulley is 8.89 kgm².

The angular acceleration of the pulley is calculated as follows;

[tex]\alpha = \frac{\omega_f - \omega _i}{t}[/tex]

where;

Final angular velocity in radian per second is calculated as

[tex]\omega _f = 17 \frac{rev}{\min} \times \frac{2\pi \ rad}{1 \ rev} \times \frac{1\min}{60 \ s} = 1.78 \ rad/s[/tex]

Now, solve for angular acceleration

[tex]\alpha = \frac{1.78-0}{5} \\\\\alpha = 0.36 \ rad/s^2[/tex]

The the moment of inertia of Pulley is determined using the formula for torque.

Iα = Fr

I = Fr/α

I = (16 x 0.2)/(0.36)

I = 8.89 kgm²

Thus, the moment of inertia of Pulley is 8.89 kgm².

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Answer:

B. Attract each other with a force of 10 newtons.

Explanation:

Statement is incorrectly written. The correct form is: A [tex]+10\,\mu C[/tex] charge and a [tex]-10\,\mu C[/tex] at a distance of 0.3 meters.

The two particles have charges opposite to each other, so they attract each other due to electrostatic force, described by Coulomb's Law, whose formula is described below:

[tex]F = \frac{\kappa \cdot |q_{A}|\cdot |q_{B}|}{r^{2}}[/tex] (1)

Where:

[tex]F[/tex] - Electrostatic force, in newtons.

[tex]\kappa[/tex] - Electrostatic constant, in newton-square meters per square coulomb.

[tex]|q_{A}|,|q_{B}|[/tex] - Magnitudes of electric charges, in coulombs.

[tex]r[/tex] - Distance between charges, in meters.

If we know that [tex]\kappa = 8.988\times 10^{9}\,\frac{N\cdot m^{2}}{C^{2}}[/tex], [tex]|q_{A}| = |q_{B}| = 10\times 10^{-6}\,C[/tex] and [tex]r = 0.3\,m[/tex], then the magnitude of the electrostatic force is:

[tex]F = \frac{\kappa \cdot |q_{A}|\cdot |q_{B}|}{r^{2}}[/tex]

[tex]F = 9.987\,N[/tex]

In consequence, correct answer is B.

Answer:

Wavelength = 0.66 meters

Explanation:

Given the following data;

Speed = 330 m/s

Frequency = 500 Hz

To find the wavelength;

Mathematically, wavelength is calculated using this formula;

[tex] Wavelength = \frac {speed}{frequency} [/tex]

Substituting into the equation, we have;

[tex] Wavelength = \frac {330}{500} [/tex]

Wavelength = 0.66 meters

Answer:

Explanation:

1. loftily - To do something in an arrogant manner.

He answered her in a loftily manner.

2) dispute - This is an argument or a disagreement.

There is a dispute between the friends.

3) diverged - To move in a different direction or separate from others.

The road diverged here to my town.

4) jostle - To come in contact, push, or collide with someone in a crowd .

The boy jostled his way through the crowd.

5) souvenirs - Something kept ad a reminder or taken as a memory of something or someone.

Before his dad died, he gave James his watch as a souvenir.

6) coveted - Something or someone that's greatly envied or desired.

James always covered power but didn't eventually get it.

Answer:

1 / i + 1 / o = 1 / f     thin lens equations

i = o f / (o - f)   rearranging

Lens 1:   object = 30 cm    f = 15.2 cm

i1 = 30 * 15.2 / (30 - 15.2) = 30.8 cm

o2 = 40.2 - 30/8 = 9.4 cm    distance of image 1 from lens 2

i2 = 9.4 * 15.2 / (9.4 - 15.2) = - 24.6 cm

The final image is 24.6 cm to the left of lens 2

The first image is inverted

The second image is erect (as seen from the first image)

So the final image is inverted

M = m1 * m2 = (-30.8 / 30) * (24.6 / 9.4) = -2.69

It can be deduced that the final image's distance from Lens 2 will be 30.8 cm.

By using the Lens formula, the distance will be calculated thus:

1/v + 1/u = 1/15.2

1/v + 1/30.0 = 1/15.2

v = 30.8cm

In this case, the image formed will be to the right.

Lastly, the overall magnification of the lens pair will be:

M = (30.8/30.0)[(-28.4/40.7 - 30.8)]

M = -2.94.

In conclusion, the magnification is -2.94.

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Answer:

A. Build a nest.

Explanation:

It wont do any of the other things and they need a place to sleep and lay eggs plus it is a bird

The heron birds belong to Ardeidae family. Some of the species among them are referred to as egrets or bitterns rather than a heron. A heron bird  build a nest during Spring. The correct option is A.

The heron is known as a long-legged, long-necked, fresh water and coastal birds. It a medium to large size bird with long necks and legs. They exhibit sexual dimorphism in size. The two male and female sex of the same species show distinct attributes beyond their difference in sexual organs.

Almost all the heron species are found in water and they are essentially non-swimming water birds which feed on the margins of lakes, ponds, sea, rivers and swamps. The small species of heron are generally referred to as the dwarf bittern.

The nesting season indicates the time of year during which birds build nests and lay eggs in them. In most cases bring up their young. It is in the spring season lot of food are available.

Thus the correct option is A.

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Given the wavelength of the visible light photon, the energy of the photon is 3.54 × 10⁻¹⁹J

Given the data in the question;

Wavelength of visible light; [tex]\lambda = 560.6 nm = 5.606*10^{-7}m[/tex]

Speed of light; [tex]c = 2.998 * 10^8 m/s[/tex]

Planck's constant; [tex]h = 6.626 * 10^{-34} J.s[/tex]

The energy and wavelength of light are related by the equation:

[tex]E = \frac{hc}{\lambda}[/tex]

Where E is energy of photon in Joules, h is Planck's constant, c is the speed of light and λ is the wavelength,

We substitute our given value into the equation

[tex]E = \frac{(6.626*10^{-34}J.s)(2.998*10^8m/s)}{5.606*10^{-7}m} \\\\E = \frac{(1.986*10^{-25}J.m}{5.606*10^{-7}m}\\\\E = 3.54 * 10^{-19}J[/tex]

Therefore, given the wavelength of the visible light photon,  the energy of the photon is 3.54 × 10⁻¹⁹J

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Answer:

Pros of DNA phenotyping:

-Phenotypical characteristics can be predicted such as eye color, hair color, skin pigmentation, and many more.

-predict ancestry of an organism

-Use to find criminals

Cons of DNA phenotyping:

-Some phenotypical traits could not be predicted

- Invading privacy

This technology will surely help forensics, law enforcement as it helps track down unknown perpetrators of crime.

3 arguments for it:

- accurate in narrow down researches

- finding biological ancestry

3 arguments against it

It violates the privacy policy of an individual

Racial discrimination is done of public

Equality policies are not followed by it.