**Answer:**

Simple machines are useful because they reduce effort needed for people to perform tasks beyond their normal capabilities.

**Explanation:**

**Answer:**

**Simple machines are useful because they reduce effort needed for people to perform tasks beyond their normal capabilities.**

**Explanation:**

Give reasons.

a. A stretched catapult has potential energy.

b A stone on ground has zero energy.

C. Rolling a drum is work against friction.

d. Lifting a stone is work against gravity.

e. Work and energy both have same unit.

a. A stretched catapult can do work when released so it must have potential energy.

b. A stone on the ground will not move on its own ever again so it has zero energy.

c. In order to roll an object there must be a friction force between the object and the ground (otherwise it will slide)

d. To lift a stone you must overcome the weight which is the force due to gravity.

e. Work and energy are both measured in Joules.

b. A stone on the ground will not move on its own ever again so it has zero energy.

c. In order to roll an object there must be a friction force between the object and the ground (otherwise it will slide)

d. To lift a stone you must overcome the weight which is the force due to gravity.

e. Work and energy are both measured in Joules.

Which property describes the number of waves that move past a point each second.

A) Speed

B) Frequency

C) Period

D) Wavelength

**Answer:B) Frequency**

**Explanation:**

**Answer:**

B) Frequency

**Explanation:**

1. Which of the following provides a correct answer for a problem that can be solved using the kinematic equations?

A A body starts from rest and accelerates at 8 m/s/s for 3 s. The body's final

position is 32 m.

B A body starts from rest and accelerates at 8 m/s/s for 3 s. The body's final

velocity is 16 m/s

C A body starts from rest and accelerates at 8 m/s/s for 3 s. The body's travels a

distance of 16 m

A body starts from rest and accelerates at 8 m/s/s for 3 s. The body's final

velocity is 24 m/s

E A body starts from rest and accelerates at 8 m/s/s for 3 s. The body's final

position is 30 m.

1 of 14

2

3

5 6 7 8

9

**Answer:**

12

**Explanation:**

12

Yodelin has fifty quarters and dimes. Their total value is $9.80. Which of these systems of equations can be used to find the number of quarters (q) and

dimes (d) Yodelin has?

**Answer:**

**q + d = 50
**

**
25q + 10d = 980
**

**Explanation:**

The equation that can be employed to determine the number of quarters(q), as well as, dimes(d) that Yodelin has would be:

q + d = 50...(1)

25q + 10d = 980...(2)

Multiplying (1) by 25

25q + 25d = 1250 ...(3)

25q + 10d = 980...(4)

subtracting (4) from (3)

15d = 270

d = 18

q = 50 - 18

= 32

The **system** of the **equations** could be

**q + d = 50**

**25q + 10d = 980**

Since Yodelin has **fifty quarters** and **dimes**. Their total value is $9.80.

So here the equations be

q + d = 50...(1)

25q + 10d = 980...(2)

Now we have to **Multiplying** (1) by 25

So,

25q + 25d = 1250 ...(3)

25q + 10d = 980...(4)

Now

subtracting (4) from (3)

15d = 270

d = 18

So,

q = 50 - 18

= 32

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matter makes up all ? and ?

and All lives matter

￼Calculate the TOTAL mechanical energy of pendulum is it swings from his highest point to its lowest point. ￼Pendulum mass is 4 kg. Use your equations for gravitational potential energy and kinetic energy to determine these values based on the data given below. Total energy is the sum of gravitational potential energy and kinetic energy. In this problem, round gravity to: g = 10 m/s^2.

**Answer:**

its should be 2.0 and 4.5 on it

7. A car is moving at 50.0 mph when the driver applies brakes. Determine the distance it

covers before coming to a halt. Coefficient of static friction between the tires and surface of

the road is 0.514. Mass of the car is 1000 kg.

**Answer:**

The distance to come to a halt is approximately 49.53 meters

**Explanation:**

Thee given parameters are;

The speed of the car, v = 50 mph = 22.35 m/s

The mass of the car, m = 1000 kg

The coefficient of friction, = 0.514

The force of friction of the brake = Mass × Gravity × Friction = 1000 × 9.81 × 0.514 = 5042.34 N

The initial kinetic energy of the car = 1/2×m×v² = 1/2 × 1000 × 22.35² = 249761.25 J

The work done by the brake = Force of the brake × Distance, d, to come to halt

By conservation of energy, we have;

The work done by the brake = The initial kinetic energy of the car

∴ The initial kinetic energy of the car = Force of the brake × Distance, d, to come to halt

The initial kinetic energy of the car = 249761.25 J = 5042.34 N × Distance, d, to come to halt

∴The distance to come to a halt = 249761.25 J /(5042.34 N) ≈ 49.53 meters

The distance to come to a halt ≈ 49.53 meters.

The car will cover **49.65 m **distance before** stopping** due to application of brake.

**Given data:**

The **mass** of car is, **M = 1000 kg**.

The initial **speed **of car is, **u = 50.0 mph = (50)(0.447 m/s) = 22.35 m/s**.

The coefficient of static friction is, [tex]\mu = 0.514[/tex].

The given problem can be solved using the third kinematic equation of motion. Which is,

[tex]v^{2}=u^{2}+2as[/tex] ....................................................(1)

Here, **v **is the final speed, **v = 0 **(Because car is finally stopping)

**s **is the **distance** covered before stopping and **a **is the magnitude of **acceleration**.

Now, since **frictional force** opposes the motion. Then,

[tex]F = f\\\\ma = \mu \times m \times g\\\\a = 0.514 \times 9.8\\\\a =5.03 \;\rm m/s^{2}[/tex]

Substituting the values in equation (1) as,

[tex]0^{2}=23.35^{2}+2(-5.03)s\\\\s = \dfrac{2500}{2 \times 5.03}\\\\ s=49.65 \;\rm m[/tex]

Thus, the car will cover **49.65 m **distance before** stopping** due to application of **brake**.

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A student is on a skateboard facing a wall. The student and skateboard have a mass of 75 kilograms. The student pushes off of the wall with a force of 100 Newtons. What is the force of the wall pushing back on the student? What is the acceleration of the student as she moves away from the wall?

**Answer:**

F=-100N; a=1.3m/s^2

**Explanation:**

Force is being made by student, so wall counteracts that force by not moving so it is equally opposite.

The **force **of the wall pushing back on the student would be 100 Newtons, and the **acceleration **of the student as she moves away from the wall would be 1.33 m/s²

Newton's third law of **motion **state that for every action force there exists a complementary **reaction **force that balances it.

As given in the problem a student is on a skateboard facing a wall. The student and skateboard have a mass of 75 kilograms. The student pushes off of the wall with a **force **of 100 Newtons,

The force of the wall **pushing **back the student = 100 Newtons

The **acceleration **of the student = 100/75

=1.33 m/s²

Thus, The student would be pushed back against the wall by a force of 100 Newtons, and she would **accelerate **away from the wall at a rate of 1.33 m/s².

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Three toy boats with the same mass were in a lake. Two boats were moving and one was stopped. Each boat got bumped by another boat, but not in the same direction. All the boats changed speed as a result of being bumped. Use the information in the diagram to answer. Which toy boat exprienced the strongest force when it was bumped ? How do you know ?

The answer is " The orange and gray toy boats experienced the strongest force because both gained the same force as they sped up the blue boat lost force so it slow down

**Explanation:**

Trust me I did this one for an assignment

The **boat** that will experience the** strongest force** is the boat that has the** highest speed**.

According to **Newton's second law** of motion, the force applied to an object is directly proportional to the product of mass and acceleration of the object.

F = ma

[tex]F = \frac{mv}{t}[/tex]

where;

The **force** **experienced** by the **boats **is directly proportional to the **velocity** of their motion. Since the **boats** have the same **mass**, the force experienced by each boat will depend on the **speed** with which the boat moves.

Thus, the **boat** that will experience the** strongest force** is the boat that has the** highest speed**.

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What is the name of the kind of stretch that involves stretching as far as you can and then holding for 10-30 seconds

Question 2 options:

PNF

ballistic

dynamic

static

Answer:

Static stretching.

Explanation:

It is static stretching because it is a form of stretching which u can do actively for a period of time and you hold position for about 30 to 60 seconds which allow the muscles and connective tissues to lengthen. It is done after work out with out movement in order to loosen up muscles so as to gain flexibility.

Find the resultant of an easterly force of 100 N and a southeast force of 80 N acting at 65 degrees to the 100 N force

**Answer:**

Resultant is 152 N at 28.5 degrees south to the 100 N force

**Explanation:**

protons are present in sodium atom.

a 11

b 10

C 12

d 9

11

**Explanation:**

There are 11 protons in a sodium atom

Which event is an example of condensation?

A. Wet clothes are drying on a clothesline.

B. A mirror fogs up when someone takes a hot shower.

C. Water drips from an icicle on the edge of a roof.

O D. Rain turns to sleet as it nears the ground.

**Answer:**

the answer to your question is b a mirror fogs up when someone takes a hot shower.

The process of conversion of **gaseous water** to its liquid form is called condensation. The **fogs** formed on the **mirror** from the hot shower is an example of** condensation**.

**Condensation** is the process of cooling up of water vapor to liquid water. Water vapor condenses when it cools. Condensation can be best understood from the reason behind raining.

When **water vaporizers** from resources and cools from the sky, and the vapor condenses to form **liquid droplets**. Similarly we can observe water droplets in the window pane due to the similar effect.

The **water vapor** arises from the hot shower condenses in the atmosphere and forms the drops on the mirror. Therefore, the mirror **fogs up** by the hot shower is an example of condensation.

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Will was riding his bike when a dog ran out in front of him. He slammed on his brakes. During this quick stop, some of the mechanical energy (his motion) was changed into

A) heat energy.

B) light energy.

C) kinetic energy.

D) gravitational energy.

**Answer:**

A

**Explanation:**

big brain

During this quick stop, some of the mechanical energy (his motion) was changed into** heat energy. **

**Energy** is the ability to do work. There are different types of **energy** such as **Heat energy**, light energy, kinetic energy, and** gravitational energy.**

**Heat** is the energy that moves from one body to another when temperatures are different. Heat passes from the** hotter **to the** colder **body when two bodies with differing **temperatures** are brought together.

The** joule** is a unit of energy that serves as the SI unit for heat (J). The calorie (cal), which is defined as "the **amount** of heat necessary to raise the temperature of one gram of water from **14.5 degrees** Celsius to 15.5 degrees Celsius," is another common unit of **heat** measurement.

Therefore, During this quick stop, some of the mechanical energy (his motion) was changed into** heat energy. **

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how much force is needed to accelerate 300 kg at a rate of 4 m/s/s

**Answer:**

1200

**Explanation:**

Force = Mass x Acceleration

**Answer:**

[tex]\boxed {\tt 1,200 \ Newtons }[/tex]

**Explanation:**

Force can be found by multiplying the mass by the acceleration.

[tex]F=m*a[/tex]

The mass is 300 kilograms.

The acceleration is 4 meters per second squared.

[tex]m= 300 \ kg\\a= 4 \ m/s^2[/tex]

Substitute the values into the formula.

[tex]F= 300 \ kg * 4 \ m/s^2[/tex]

Multiply.

[tex]F= 1200 \ kg * m/s^2[/tex]

1 Newton is equal to 1 kilograms meters per second squared, so our current answer of 1200 kg m/s² is equal to 1200 Newtons.

[tex]F= 1200 \ N[/tex]

The force needed is **1,200 Newtons.**

Protons are found only in the atomic nucleus.

TRUE

FALSE

**Answer:**

true

**Explanation:**

Protons and neutrons are found in the nucleus

Question 4 of 20

Luke wraps a magnetized steel nail with several coils of insulated wire and

then connects the loose ends of the wire to a 10 W lightbulb. Which step

could he take next to get the lightbulb to light up?

O A. Replace the magnetized nail with a nonmagnetic metal to cause

an electric current to flow in the wire.

O B. Remove the magnetized nail from the wire coil to induce a

magnetic field that will flow through the wire.

C. Move the magnetized nail back and forth within the wire coil to

induce an electric current in the wire.

D. Add several more coils of the wire around the magnetized nail to

make a stronger electric current.

SUBMIT

Answer:

C. Move the magnetized nail back and forth within the wire coil to induce an electric current in the wire.

Hope this helps.

An ant is crawling along a yardstick that is pointed with the 0-inch mark to the east and the 36-inch mark to the west. It starts at the 14-inch mark, crawls to the 20-inch mark, then moves to the 16-inch mark. What was the total distance the ant traveled?

**Given :**

An ant is crawling along a yardstick that is pointed with the 0-inch mark to the east and the 36-inch mark to the west.

It starts at the 14-inch mark, crawls to the 20-inch mark, then moves to the 16-inch mark.

**To Find :**

The total distance the ant traveled.

**Solution :**

Total distance travelled by ant = (distance between 14 and 20 inch mark) +

(distance between 20 and 16 inch mark)

Total distance = (20-14 ) + ( 20-16) = 6 + 4 = 10 inch.

Therefore, **total distance the ant traveled is 10 inch.**

Hence, this is the required solution.

A force of 75 N at an angle of 15° to the direction of motion moves a chair 3 m. Which change would result in more work being done on the chair?

Answer:

Decreasing the angle to 10

Explanation:

Edge 2020

Dos pilotos suicidas, que están inicialmente a una distancia de 500 m entre sí, deciden chocar directamente de frente arrancando ambos desde el reposo. Ambos autos pueden desarrollar una aceleración máxima constante de 15 m/s2 . Si el piloto A arranca un segundo antes que el piloto B, encuentra: a) la posición donde los autos chocan, medida a partir de la posición donde arranca el piloto A, y b) la rapidez relativa de la colisión (la rapidez de B con respecto a A justo antes de la colisión, ó viceversa).

**Answer:**

a) El punto de colisión de los dos automóviles desde donde parte el conductor del automóvil A es de aproximadamente 293,14 metros.

b) La velocidad del automóvil A, en relación con la velocidad del automóvil B, es de 15 m / s

**Explanation:**

Los parámetros del movimiento son;

La distancia entre ambos coches = 500 m

La aceleración de ambos coches = 15 m / s²

La dirección de movimiento de ambos coches = uno hacia el otro

La hora de inicio del conductor A = Un segundo antes de la hora de inicio del conductor B

Por lo tanto, de la ecuación de movimiento, tenemos;

s = u · t + 1/2 · a · t²

v² = u² + 2 · a · s

Dónde;

u = La velocidad inicial de los autos = 0 (los autos parten del reposo)

t = El tiempo de movimiento de una aceleración dada

a = La aceleración = 15 m / s²

s = La distancia recorrida en el tiempo t

Por lo tanto, para el controlador A, tenemos;

s₁ = 0 × (t + 1) + 1/2 × 15 × (t + 1) ² = 7.5 × (t + 1) ²

s₁ = 7.5 × (t + 1) ²

Para el conductor B, tenemos;

s₂ = 0 × t + 1/2 × 15 × t² = 7.5 × t²

s₂ = 7,5 × t²

Dado que ambos chocan a lo largo del camino de 500 m, tenemos;

s₁ + s₂ = 500 metros

∴ 7.5 × (t + 1) ² + 7.5 × t² = 500

∵ s₁ + s₂ = 7.5 × (t + 1) ² + 7.5 × t²

Lo que da;

15 · t² + 15 · t + 7.5 = 500

15 · t² + 15 · t - 492,5 = 0

Resolver usando la aplicación en línea da; t = -6,25181 o t = 5,25181

Dado que t es un número natural, tenemos el valor correcto para t = 5.25181 segundos

a) Por tanto, el punto de colisión de los dos coches desde donde parte el conductor del coche A es;

s₁ = 7.5 × (t + 1) ² = 7.5 × (5.25181 + 1) ² ≈ 293.14 metros

El punto de colisión de los dos automóviles desde donde parte el conductor del automóvil A ≈ 293,14 metros

b) La semilla de A en el punto de colisión se da de la siguiente manera

Velocidad, v₁ = u + a × (t + 1) = 0 + 15 × (5.25181 + 1) ≈ 93.78

v₁ ≈ 93,78 m / s

La semilla de B en el punto de colisión también se da de la siguiente manera

Velocidad, v = u + a × (t) = 0 + 15 × 5.25181 ≈ 78.78

v₁ ≈ 78,78 m / s

Por lo tanto, la velocidad del automóvil A, en relación con la velocidad del automóvil B, [tex]v_{relative}[/tex] se da como sigue;

= v₁ - v₂ = 93,78 m / s - 78,78 m / s = 15 m / s

la velocidad del automóvil A, relativa a la velocidad del automóvil B = 15 m/s.

Which model of the atom has electrons traveling in specific paths around the nucleus? Bohr's model Rutherford's model Thomson's model Dalton's model

**Answer:**

A, Bohr's model

**Explanation:**

Took the quiz, hope it's right for you.

(The other three did have something to do with it they just didn't create that specific model)

The **model** of the atom that has **electrons** traveling in specific paths around the nucleus is **Rutherford's model**.

Therefore, the correct answer is option **B**

**J. J Thomson** proposed that the atom is a sphere of positively charged matter in which negatively charged electron are embedded.

**In Rutherford's model **of atomic structure, the electrons moves in orbits by electrostatic attraction to the positively charged nucleus.

According to **Dalton's atomic theory**, atom were indestructible and indivisible solid particle.

**Bohr's model** made assumption that electron can only exist in circular orbits of definite quantum energy.

According to the question, the model of the atom that has electrons traveling in specific paths around the nucleus is Rutherford's model.

Therefore, the correct answer is **option B**

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How are velocity, wavelength, and frequency related

**Answer:**

The wave velocity and the wavelength are related to the wave's frequency and period by vw=λT or vw=fλ. The time for one complete wave cycle is the period T. The number of waves per unit time is the frequency ƒ. The wave frequency and the period are inversely related to one another.

**Explanation:**

#7 If the Moon’s mass was suddenly tripled, what would occur to the gravitational force between the Earth and the Moon?

(A) Gravitational force would increase by a factor of 3.

(B) Gravitational force would decrease by a factor of 3.

(C) Gravitational force would increase by a factor of 9.

(D) Gravitational force would decrease by a factor of 9.

**Answer:**

well it would be (A) Gravitational force would increase by a factor of 3.

**Explanation:**

**because the moon is the only thing that gained mass not the Earth**

List out Units For: Acceleration

Acceleration units : M/s squared

Unit for Acceleration is m/s² or ms raised to -2

The photo shows dew drops that formed on the grass when temperatures

cooled during the night. Which change of state happened to form the dew?

A. Liquid to gas

B. Gas to liquid

C. Solid to gas

D. Gas to solid

Gas to a liquid

This is because of condensation

This is because of condensation

gas to liquid is the answer

Eclipses occur because the Moon?

A

does not create its own light and only reflects light from the Sun.

o

does not create its own light and only reflects the light from Earth.

o

с

creates its own light, which is blocked by the Sun during an eclipse.

creates its own light, which is blocked by Earth during an eclipse.

I’m just here typing don’t mind me

**Answer:**

с

creates its own light, which is blocked by the Sun during an eclipse.

**Explanation:**

might not be right but its what i remember

Which words help you to determine the meaning of the word decelerate in paragraph 3

**Answer:**

the words

**Explanation:**

**Answer:**

Pressing the brake pedal

**Explanation:**

Decelerate sounds a lot like the word accelerate, but we know that the speed is decreasing, so it would have to be going down, getting slower, so whichever sounds like a good example of speed decreasing should be a good answer!

please help

Which equipment is best to hold and to measure liquids?

A). flask and graduated cylinder

B). scale and ruler

C). caliper and thermometer

D). stopwatch and beaker

**Answer:**

I'm pretty sure that the answer is A

If an object is moving with constant acceleration, its velocity must

a

change by varying amounts depending on its speed.

b

always decrease.

c

be constant also.

d

change by the same amount each second.

change by the same amount each second. i think

which one of the following is a derived Si unit a. Newton, b. Meter, c. Mole, d. Kiogram

**Answer:**

*The SI is founded on seven SI base units for seven base quantities assumed to ... The SI derived units for these derived quantities are obtained from these ... mass density, kilogram per cubic meter, kg/m3 ... amount-of-substance concentration, mole per cubic meter, mol/m3 ... solid angle, steradian (a), sr (c), -, m2·m-2 = 1 (b).*

**Kilogram** is a derived **SI unit **of the following.

Thus, A universal standard for expressing the **magnitudes** or quantities of significant natural events is the** International System of Units. **

The acronym** SI,** which derives from the French term Systèm international stands for the** System of Units**, also known as the metric system. The meter-kilogram-second (MKS) system, an earlier unit of measurement, serves as the foundation for the** SI standard.**

The **SI standard **is promoted and explained by the Bureau international des poids et **mesures** (BIPM). The organization was founded in 1875 and is known as the International** Bureau** of Weights and Measures in English. It is governed by the **International Committee** for Weights and Measures (CIPM).

Thus,** Kilogram** is a derived **SI unit **of the following.

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Write the product using exponents.(-4).(-4).(-4).y.y
you just purchased new tennis shoes for basketball for $99 the cost for washing will be $2.00. you will wear them 110 times between basketball practice and games. what is the cost per wearing?
-4 5/6 + (3 1/3) =How dI you do this?
Which relationship between x and y in the equation shows a proportional relationship?A y=x2B y=5(x+3)C y = 5x + 3D y = 3x
Question 114 ptsUsing the formula 2H202 --> 2H2O + O2, if 7.30 moles of peroxide aredecomposed, how many moles of oxygen will be formed?
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Round 0.00208815 to 3 significant figures
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Please Assist!What is the answer to this question???
Describe one possible consequence of not having social or emotional needs met.
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After winning the French & Indian War, Great Britain passed the Proclamation of 1763. Why did this anger the colonists? A. It took away their representation in Parliament. B. It forced colonists to house and feed British soldiers. C. It passed a tax on items such as newspapers, wills, and contracts. D. It did not allow them to settle on land west of the Appalachian Mountains.
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Creating Lake-Effect SnowSituated on Lake Erie, the city of Buffalo, New York, is one of the snowiest cities in the United States. Like other cities on large lakes, it is subject to a phenomenon called lake-effect snow. Water retains heat, so lake water is often warmer than the air. In the lake effect, cold air moves over warmer lake water, initiating a process that can produce large snowstorms. Moisture from the lake evaporates into the cold air, warming it. Because warm air is less dense than cold air, it begins to rise. As it rises and moves away from the lake, it cools down. As the air cools, moisture condenses and forms into clouds. If the temperature is cold enough, the moisture falls to the ground as snow.What is the main idea of the passage?A, When cold air moves over the warmer water of a lake, lake effect snow can be produced.B, In the lake effect, warm air, which is lighter than cold air, rises and moves away.C, Buffalo, New York, gets more snow than most cities in the United States.
What is the capital of N. Ireland?