Why is physical activity important?
O It helps keep you healthy.
It helps control your weight
It helps imcove your balance and coordination
All of the Above
at least one activity you can enjoy to help you get your 60 min

Answer:

The amount of mechanical energy produced by the old lorry when 600 Joules of chemical energy have been used by the engine, M.E. is 120 Joules

Explanation:

The question is a word problem on the relationship between energy efficiency and energy consumption

The given parameters of the old lorry are;

The chemical energy to mechanical energy conversion efficiency of the old lorry = 20%

The amount of chemical energy used by the engine = 600 joules

Let 'M.E.' represent the amount of mechanical energy produced by the old lorry, we have;

[tex]Energy \ Efficiency = \dfrac{Energy \ produced }{Total \ Energy \ Taken \ In \ or \ Used} \times 100[/tex]

Therefore, the for the old lorry, we have;

[tex]20\% = \dfrac{M.E. \ Produced}{600 \ Joules} \times 100[/tex]

∴ M.E. Produced = 20/100 × 600 J = 120 J

The amount of mechanical energy produced by the old lorry when 600 Joules of chemical energy have been used by the engine, M.E. = 120 Joules

Answer:

[tex]R = 1.5* 10^{-10}m[/tex]

Explanation:

Given

[tex]r = 2.5 * 10^{-11}m[/tex] -- radius of hydrogen atom

See attachment

Required

Determine the radius of magnesium atom (R)

From the attachment, the ratio of a hydrogen atom to a magnesium atom is:

[tex]Ratio = 6mm : 36mm[/tex]

Simplify

[tex]Ratio =1 : 6[/tex]

Represent the radius as ratio:

[tex]Ratio = r : R[/tex]

Substitute [tex]r = 2.5 * 10^{-11}m[/tex]

[tex]Ratio = 2.5 * 10^{-11}m : R[/tex]

Equate both ratios

[tex]2.5 * 10^{-11}m : R = 1 : 6[/tex]

Express as fraction

[tex]\frac{2.5 * 10^{-11}m}{R} = \frac{1}{6}[/tex]

Cross Multiply

[tex]R * 1 = 2.5 * 10^{-11}m * 6[/tex]

[tex]R * 1 = 2.5 * 6* 10^{-11}m[/tex]

[tex]R * 1 = 15* 10^{-11}m[/tex]

[tex]R = 15* 10^{-11}m[/tex]

[tex]R = 1.5*10* 10^{-11}m[/tex]

[tex]R = 1.5* 10^{1-11}m[/tex]

[tex]R = 1.5* 10^{-10}m[/tex]

Hence, the radius of the magnesium atom is: [tex]1.5* 10^{-10}m[/tex]

Explanation:

Girls have two X Chromosomes while boys have one X Chromosome and, as you now know, one Y Chromosome. So girls are XX and boys are XY.

Answer: The X and Y chromosomes, also known as the sex chromosomes, determine the biological sex of an individual: females inherit an X chromosome from the father for a XX genotype, while males inherit a Y chromosome from the father for a XY genotype (mothers only pass on X chromosomes).

Explanation:

Answer:

Has the same properties as it's parts

Explanation:

Answer:

t = 4.19 s,   θ = 0.437 rad

Explanation:

This is an exercise in rotational kinematics in this case we indicate the angular velocity and the angular acceleration, asking for the time and the angle it takes to stop.

          w = w₀ + α t

          w² = w₀² + 2 α θ

when the system stops the angular velocity is zero

          0 = w₀- α t

          0 = w₀² - 2 α θ

          t = w₀ / α

          tea = w₀² / 2 α

let's reduce the magnitudes to the SI system

          w₀ = 2 rpm (2π rad / 1 rev) (1 min / 60s) = 0.209 rad / s

let's calculate

         t = 0.209 / 0.05

         t = 4.19 s

         θ = 0.209 2/2 0.05

         θ = 0.437 rad

Answer:

Reproduction

Explanation:

because reproduction produces variation within the species allowing the species to survive selection

Answer: D = reproduction

Explanation:

Answer:

Speed = 0.217 m/s

Explanation:

Given the following data;

Distance = 0.5m

Time = 2.3 seconds

To find the speed;

Speed = distance/time

Speed = 0.5/2.3

Speed = 0.217 m/s

Therefore, the speed of the bowling

ball is 0.217 meter per seconds.

.c ...energy

Explanation:

Amplitude does not affect wavelength. It also does not affect wave speed. Amplitude is the energy of the wave measured from the rest position to the top of the crest. A wave with more energy has a higher up crest/ higher amplitude.

As the amplitude of a mechanical wave increases, the quantity which increases is: C. energy.

A mechanical wave can be defined as a type of wave that requires a medium for its propagation and it creates a disturbance in the medium. Thus, a good example of mechanical wave is sound wave, which is typically transported in a perpendicular direction.

Amplitude refers to the maximum displacement of a wave when measured from its equilibrium position. Also, the amplitude of a mechanical wave has no effect on the following:

Read more on wave here: https://brainly.com/question/19250621

Answer:

density; thermal

Explanation:

Convection currents occur in fluids because of temperature and density differences. Convection currents transfer thermal energy throughout a fluid.

When a fluid is heated, the molecules closest to the heat source gets heated first and their temperature is raised. The rise in temperature lowers their density and as such, they move to the upper portion of the fluid to be replaced by yet-to-be-heated molecules at the upper portion.

When the replacement molecules also get heated, the same process occurs and a to-and-from rotational movement of molecules, also known as convection current, is created within the fluid. The to and from movement, thus, transfer thermal energy within the fluid until all the molecules within the fluid are at the same temperature.

Answer

density; thermal

Explanation:

its right i just did it

Answer:

hola

Explanation:

jffkbjkcvncncjcncjcjchchchcjcjcjcjcjckgmndjekbm hdfstfm mvndbfncn bdhwhgmvmch

Answer:

The answer is W

Answer:

Uv rays

Explanation:

ultraviolet rays of the suun gives force

Answer:

what zones

Explanation:

Answer:

Gravity

Gravity as well as electrostatic and magnetic attraction and repulsion provide real life examples of forces being exerted by one object on another without them being in contact with each other. Many children are aware of magnetism and have played with fridge magnets.

Explanation:

A force that one object can apply to another object without touching it is Gravity.

Gravity is the force of attraction between the two objects separated by a particular distance. Gravity force is exerted on every object present in the universe.

Gravity as well as electrostatic and magnetic attraction and repulsion provide real-life examples of forces being exerted by one object on another without them being in contact with each other. Many children are aware of magnetism and have played with fridge magnets.

Therefore force that one object can apply to another object without touching it is Gravity.

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Answer:

It provides shape and support for the body

Explanation:

Providing shape and support for the body is one of the many functions of the skeletal system, which is directly helpful to the circulatory system. Thus, the correct option is D.

The skeletal system is the body's central framework. This system consists of bones and connective tissue, including the cartilage, tendons, and ligaments. The system is also called the musculoskeletal system. It is made up of 206 bones.

The human skeleton serves six main functions which are providing support, movement of the body, protection, production of blood cells such as red blood cells and white blood cells, storage of ions such as calcium and phosphorus, and the endocrine regulation. Bone is a hard, dense connective tissue which is responsible for forming most of the adult skeleton, the support structure of the body of an organism.

Providing shape and support for the body is the function which is directly helpful to the circulatory system of the body.

Therefore, the correct option is D.

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Answer:

Beth went back toward her origin

Explanation:

Answer:

B

Explanation:

Hope this helps :)

Answer:

Frequency of wave = 2.16 Hz (Approx)

Explanation:

Given:

Speed of tsunami = 970 km/h

Wavelength = 450 km

Find:

Frequency of wave

Computation:

Frequency = Speed / Wavelength

Frequency of wave = Speed of tsunami / Wavelength

Frequency of wave = 970 / 450

Frequency of wave = 2.16 Hz (Approx)

Answer: The number of complete wavelengths in a given unit of time is called frequency (f). As a wavelength increases in size, its frequency and energy (E) decrease. From these equations you may realize that as the frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer.

Explanation:

In addition to the resultant force acting on an object, the mass of the object should be known to find the acceleration. So, the mass is the answer.

Newton's second law of motion states that

a = F / m

Where:

a is the acceleration of the object,

The net force acting on the object is F

m is the mass of the object.

By dividing the net force (F) by the mass (m), you can determine the acceleration (a) of the object.

So, both the net force and the mass are necessary to calculate the acceleration. So, the mass is the answer.

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Answer:

Impulse=18Ns

Explanation:

Impulse= force*time

Plug in known values...

I=6N*3s

I=18Ns

The impulse  produced by the force is 18Ns

What is Impulse?

Given:

F= 6.0N

t= 3.0 s

On substituting these values in the above formula:

[tex]I=6N*3s\\ \\I=18Ns[/tex]

Thus, The impulse  produced by the force is 18 Ns.

Learn more:

brainly.com/question/14073258

Explanation:

The solution is be found in the attachment.

A horizontal net force F is exerted on an object at rest. The object starts at x = 0 m and has a speed of 4.0 m/s after moving 8.0 m along a horizontal frictionless surface. The net force F as a function of the object's position x is shown below.

What is the mass of the object?

Answer: 30 kg

Explanation:

As an astronaut travel far away from the earth her weight Decreases because weight depends upon the acceleration due to gravity and in space there is no gravity.

Answer:

0 becouse it will still before falling

Explanation:

Answer:

a. running

Explanation:

because you are using  more energy

Answer:

In mechanical terms, person A who walks slowly for most of the way then runs the last few steps does more work than person B who runs most of the way then walks slowly the last few steps. Person B uses more energy than person A, but this is a separate issue about the difference between external and internal work.

Explanation:

sourced from comminity fitbit

Answer:

Explanation:

People are wild about amusement parks. Each day, we flock by the millions to the nearest park, paying a sizable hunk of money to wait in long lines for a short 60-second ride on our favorite roller coaster. The thought prompts one to consider what is it about a roller coaster ride that provides such widespread excitement among so many of us and such dreadful fear in the rest? Is our excitement about coasters due to their high speeds? Absolutely not! In fact, it would be foolish to spend so much time and money to ride a selection of roller coasters if it were for reasons of speed. It is more than likely that most of us sustain higher speeds on our ride along the interstate highway on the way to the amusement park than we do once we enter the park. The thrill of roller coasters is not due to their speed, but rather due to their accelerations and to the feelings of weightlessness and weightiness that they produce. Roller coasters thrill us because of their ability to accelerate us downward one moment and upwards the next; leftwards one moment and rightwards the next. Roller coasters are about acceleration; that's what makes them thrilling. And in this part of Lesson 2, we will focus on the centripetal acceleration experienced by riders within the circular-shaped sections of a roller coaster track. These sections include the clothoid loops (that we will approximate as a circle), the sharp 180-degree banked turns, and the small dips and hills found along otherwise straight sections of the track.

Answer:

The correct answer is "-1.5 cm".

Explanation:

The given values are:

Object is placed,

u = 2.5 cm

Focal length,

f = 1.5 cm

On applying the lens formula, we get

⇒ [tex]\frac{1}{u} +\frac{1}{v} =\frac{1}{f}[/tex]

or,

⇒ [tex]\frac{1}{v} =\frac{1}{u} -\frac{1}{f}[/tex]

On substituting the given values, we get

⇒    [tex]=\frac{1}{2.5} -\frac{1}{1.5}[/tex]

⇒    [tex]=\frac{1.5-2.5}{3.75}[/tex]

⇒    [tex]=\frac{-1}{3.75}[/tex]

⇒ [tex]v=-3.75 \ cm[/tex]

As we know,

Magnification, [tex]m=\frac{v}{u}[/tex]

On substituting the values, we get

⇒                           [tex]=\frac{-3.75}{2.5}[/tex]

⇒                           [tex]=-1.5 \ cm[/tex]

Answer:

The braking distance of the car is 40 m

Explanation:

The two steps are;

1) Calculation (finding) of the initial kinetic energy , K.E., of the car

2) Calculation (finding) of the braking distance from the calculated K.E., of the car

The initial Kinetic energy of the car, K.E. = 1/2×m×v²

Where;

m = The mass of the car = 1,600 kg

v = The velocity of the car = 20 m/s

∴ K.E. = 1/2 × 1,600 kg × (20 m/s)² = 320,000 joules

2) The work done in stopping the car, W = The braking force, 'F' × The braking distance, 'd'

∴ W = F × d

Where;

F = The braking force = 8,000 N

d = The braking distance of the car

By energy conservation principle, the work, 'W', that is required to stop the car = The initial kinetic energy of the car, K.E.

∴ W = K.E. = 320,000 joules

Therefore, by substituting the known values for the variables, we have;

320,000 J = 8,000 N × d

∴ d = 320,000 J/(8,000 N) = 40 m

The braking distance of the car, 'd' = 40 m.