Grade 8 Science Admin. May 2018 Released
37 A physics teacher performed a demonstration for a science class by pulling a crate across the
floor and measuring the force with a spring scale. While she pulled, a student measured the
acceleration of the crate with a handheld electronic device. The results of three trials are
shown below
Motion
F = 900 N
Actual Acceleration
of Crate
Trial
1
140 kg
Acceleration
(m/s)
0.36
0.34
0.38
0.36
2
3
Average
The teacher asked the class to calculate the acceleration of the crate based on the crate's
mass and the force she applied. What conclusion can be made about the difference between
the calculated acceleration and the actual acceleration that occurred in the trials?
A Another force in the direction of the motion produced a lower acceleration than calculated.
B An opposing force caused by friction produced a lower acceleration than calculated.
C Another force in the direction of the motion produced a higher acceleration than
calculated.
D An opposing force caused by friction produced a higher acceleration than calculated,

Answers

Answer 1

Answer:

B. An opposing force caused by friction produced a lower acceleration than calculated

Explanation:

Answer 2

Answer:

An opposing force caused by friction produced a lower acceleration than calculated.

Explanation:


Related Questions

a quickly moving house cat has 10 j of kinetic energy at speed v. at what speed will the cat have 20 j of kinetic energy

Answers

Answer:

2.00v

Explanation:

Se colocan tres objetos, muy cerca uno del otro, dos al mismo tiempo. Cuando se juntan los objetos A y B, se repelen. Cuando se acercan los objetos B y C, se repelen. De los siguientes enunciados, ¿cuál es el verdadero? a) Los objetos A y C tienen cargas del mismo signo. b) Los objetos A y C poseen cargas de signos opuestos. c) Los tres objetos tienen cargas de distinto signo. d) Uno de los objetos es neutro. e) Es necesario llevar a cabo experimentos adicionales para determinar los signos de las cargas.

Answers

Answer:

Los objetos A y C tienen cargas del mismo signo (opcion a)

Explanation:

Hay dos tipos de cargas : cargas positivas y cargas negativas.

La Ley de Coulomb dice que la fuerza electrostática entre dos cargas puntuales es proporcional al producto de las cargas e inversamente proporcional al cuadrado de la distancia que las separa, y tiene la dirección de la línea que las une y se cumple que:

La fuerza ejercida sobre una carga apunta hacia la otra cuando las dos tienen distinto signo (fuerza atractiva). El sentido de la fuerza se dirige hacia el lado opuesto de la carga cuando ambas tienen el mismo signo (fuerza repulsiva).

Es decir que las cargas de igual signo se repelen, mientras que las de diferente signo se atraen.

Entonces, si se juntan los objetos A y B y se repelen significa que la carga es del mismo signo.

Cuando se acercan los objetos B y C, se repelen. Entonces significa que posee carga de igual signo.

Por lo que podes concluir que los objetos A y C tienen cargas del mismo signo (opcion a)

does anyone know the answer ?

Answers

Answer:

it is 2 and 3 trust me I gotcha

What task requires the most work, lifting a 12-kg sack 2 meters or lifting a 25-kg sack 1 meter?
a.) the 12-kg sack
b.) the 25-kg sack
c.) Both require the same amount of work.
d.) Impossible to determine without knowing the contents of the sack

Please answer ASAP!! Thank you!!

Answers

Multiply the masses by the respective distances:

(12 kg) (2 m) = 24 J

(25 kg) (1 m) = 25 J

so the heavier bag takes more work to lift, and (b) is the answer.

(d) is technically correct if the sacks are carrying different contents whose masses are not equal, but since we don't know what's inside each sack, assume 12 kg and 25 kg are the masses of each sack *and* their contents.

A 2 L balloon filled with gas is warmed from 280 K to 700 K. What is the volume of the gas after it is heated?

Answers

Answer:

New volume, v2 = 0.8L

Explanation:

Given the following data;

Original Volume = 2L

Original Temperature = 280K

New Temperature = 700K

To find new volume V2, we would use Charles' law.

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles is given by;

[tex] VT = K[/tex]

[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]

[tex] \frac{V1}{T1} = \frac{V2}{T2}[/tex]

Making V2 as the subject formula, we have;

[tex] V_{2}= \frac{V1}{T1} * T_{2}[/tex]

[tex] V_{2}= \frac{2}{700} * 280[/tex]

[tex] V_{2}= 0.0029 * 280[/tex]

V2 = 0.8L

Therefore, the volume of the gas after it is heated is 0.8L.

You are attempting to move a new couch into your house. You apply 200 N of force and
your friend Jake applies 150 N of force in the same direction. The friction of the couch
on the carpet resists the pushing with 100 N of force. There are five forces

Answers

Explanation:

try to write complete question

but

200 Newton + 150 Newton -100 Newton

if you are asking this

Examine the diagram of the cell cycle.


Which label identifies the step labeled W?

Anaphase: chromosomes thicken
Metaphase: chromosomes thicken
Anaphase: chromosomes are pulled apart
Metaphase: chromosomes are pulled apart

Answers

Answer:

Anaphase: chromosomes are pulled apart

Explanation:

Anaphase is a very rapid phase of meiosis and mitosis where sister chromatids (during mitosis or meiosis II) or homologous chromosomes (during meiosis I) separate and migrate to opposite poles of the cell. In the image, the diagram represents mitosis (thus separation of sister chromatids).

During this phase, following a specific signal, the sister chromatids separate abruptly. They are then "pulled" by the "microtubules" towards the pole to which they are attached. Chromatids migrate rapidly at a rate of about 1 μm / min. Anaphase is usually divided into two distinct phases.

Answer:

The answer is C

Explanation:

45 POINTS!! IF ANYONE IS WILLING TO DO THIS YOU'RE A HERO

Pretend you are in a world with no friction or air resistance. You are on your bicycle at the top of a small hill. You kick off and without pedaling, you roll down the hill. How far will you go without pedaling in this pretend world? How does it compare with how far you might go in the real world? If there is a difference between the two worlds, why is this so? Explain as precisely as you can, using the law of conservation of energy in your explanation.

A 2-4 paragraph expository essay. This will include a full explanation of the normal conditions scenario and the frictionless world scenario in paragraph form.
No matter the format, the work must include:

A description of the bike’s behavior in our normal world with friction and air resistance, including distance traveled.
A description of the bike’s behavior in a frictionless, air resistance free world including distance traveled.
An explanation of forces at play in both scenarios and the kinetic and potential energy levels of the bike at various points in its travel down the hill. This will include application of the Law of Conservation of Energy using appropriate vocabulary words.
Spelling, grammar conventions, sentence structure and visual choices that allow your reader to access the information you are providing.

Answers

Answer:

you will go no where as far as you wish because there is no air resistance or friction, causing you to not stop.  In the real world, you would stop a little bit after you got done with the hill because you have friction and air Resistance to bring you to a stop.  There is a huge difference because in real life, there is a lot of friction and air resistance in the real world, which will eventually bring someone to a stop no matter how fast they are going.  

Explanation:

Will give brainliest!! How would you write the direction of the vector above as a global angle?

Answers

Answer:

Assuming they're unit vectors (length of 1)

You simply add them together.

The vector pointing right can be described with X and Y

(1, 0).

The vector pointing down

(0, -1).

The numbers are taken from the axis in X and Y directions.

If you add them together you get a final vector.

(1, - 1)

This gives you -45° pointing South East.

Or 360°-45°=315°

Select the correct answer from each drop-down menu.
What causes atoms to form covalent bonds?
The number of
In a covalent bond, two atoms are held together by the attraction between
covalent bonds that an atom can form depends on the number of
in the atom.

Answers

Answer:

YES the first option

Explanation:

two atom are held together

Answer:

In a covalent bond, two atoms are held together by the attraction between each atom and the shared electrons. The number of covalent bonds that an atom can form depends on the number of valence electrons in the atom.

A projectile is fired with an initial speed of 37.0 m/s at an angle of 43.7 ∘ above the horizontal on a long flat firing range. What is the maximum height.

Answers

Answer:

The maximum height reached by the projectile is 33.34 m

Explanation:

Given;

initial velocity of the projectile, u = 37 m/s

angle of projection, θ = 43.7°

The maximum height reached by the projectile = ?

Apply the following kinematic equation, to determine the maximum height reached by the projectile.

Maximum height (H) is given as;

[tex]H = \frac{u^2 sin^2\theta}{2g}\\\\ H = \frac{(37)^2 (sin 43.7)^2}{2*9.8}\\\\H = 33.34 \ m[/tex]

Therefore, the maximum height reached by the projectile is 33.34 m

How are density and buoyancy related to each other?

Answers

Answer:

Buoyant force is directly proportional to the density of the fluid in which an object is immersed. Buoyancy is the tendency to rise or float in a fluid. The upward force exerted on objects submerged in fluids is called the buoyant force. where ρ is the density, V is the volume, and m is the mass of the displaced fluid.

Explanation:

Answer:

well It means the plant cells inside of a organism

What is mass and the temperature ?​

Answers

Answer:

Mass is a measure of the amount of matter in an object.

A measure of the warmth or coldness of an object or substance with reference to some standard value.

Explanation:

If two objects have the same mass, the object with the higher temperature has greater thermal energy. Temperature affects thermal energy, but temperature isn't the same thing as thermal energy. That's because an object's mass also affects its thermal energy.

Answer:

Explanation:

Mass is a measurement of how much matter is in an object. Mass is a combination of the total number of atoms, the density of the atoms, and the type of atoms in an object. Mass is usually measured in kilograms which is abbreviated as kg. In physics there are different ways of determining the quantity of mass

Temperature definition, a measure of the warmth or coldness of an object or substance with reference to some standard value. The temperature of two systems is the same when the systems are in thermal equilibrium.

Billy stands on a hill without slipping. In which direction is the force of friction acting?
A. along the surface of the hill, toward the bottom of the hill.
B. perpendicular to the surface of the hill
C. straight up
D. Along the surface of the hill toward the top of the hill.​

Answers

Answer: D. Along the surface of the hill toward the top of the hill.​

Hope I helped you!

D. Along the surface of the hill toward the top of the hill.​

The force of a plane's engine is moving the plane toward the right with 800N. Coming from the left you have
resistance forces of air with 60N and friction with 40N. What is the direction and net forces that is being applied
the plane?

Answers

Answer:es la F

Explanation:


W1 has a weight of 220 N acting 0.6m away from the pivot.
How far does W2 whose weight is 180 N need to sit for the see
saw to be in equilibrium.
&
?
W-220 N
W2 - 180N
a) 0.3 m
Ob) 0.73 m
C) 0.5m
O d) 0.83 m

Answers

Answer:

0.73m

Explanation:

Given parameters:

W1  = 220N

D1  = 0.6m

W2 = 180N

Unknown

D2 = ?

Solution:

The torque on each side must be balanced;

 Torque  = force x distance

     T₁   = T₂  

  W1  x D1  = W2 x D2

Insert the parameters and solve for D2;

   220 x 0.6  = 180 x D2

     132  = 180D2

     D2 = [tex]\frac{132}{180}[/tex]   = 0.73m

. Which color has the shortest wavelength? *
2 points
a. Violet
b. Yellow
c. Blue
d. Red

Answers

Answer:

Violet

Explanation:

Occurring to Google red has the longest while violet has the shortest. Violet is the shortest at 380 nanometers.

Answer:

violet

Explanation:

Violet has the shortest light wavelength.

Please mark brainliest. Thanks!!!!

A compressed spring does not have elastic potential energy.
O True
O False.


help please

Answers

Answer:

False

Explanation:

The second you let go its gonna release kinetic energy that's why it's potential

Calculate the average induced voltage between the tips of the wings of an airplane flying above East Lansing at a speed of 885 km/h. The wingspan of the airplane is 50.4 m, the vertical component of the Earth's magnetic field is 6.90×10-5 T.

Answers

Answer:

=0.855V

Explanation:

The induced voltage can be calculated using below expression

E =B x dA/dt

Where dA/dt = area

B= magnetic field = 6.90×10-5 T.

We were given speed of 885 km/h but we will need to convert to m/s for consistency of unit

speed = 885 km/h

speed = 885 x 10^3 m/hr

speed = 885 x 10^3/60 x60 m/s

speed = 245.8 m/s

If The aircraft wing sweep out" an area

at t= 50.4seconds then we have;

dA/dt = 50.4 x 245.8

= 123388.32m^2/s

Then from the expression above

E =B x dA/dt substitute the values of each parameters, we have

E = 6.90 x 10^-5 x 12388.32 V

E =0.855V

Hence, the average induced voltage between the tips of the wings is =0.855V

A block of mass 3 kg is pushed 1 m along a frictionless horizontal table by a constant 16 N force directed 34◦ below the horizontal. Determine the work done by the applied force. Answer in units of J.

please help i'm a struggling physics student. Thanks so much!

Answers

Answer:

W = 13.26 [J]

Explanation:

Work in physics is defined as the product of force by the distance traveled by the object.

It is important to clarify that the force should be parallel to the direction of movement. In this way, we have to decompose the force into the X component of the movement.

Fx = 16*cos(34) = 13.26 [N]

W = F*d

where:

F = force = 13.26 [N]

d = distance = 1 [m]

W = 13.26*1

W = 13.26 [J]

Answer:

the guy above me is correct

Explanation:

If a force of 12 N is applied to an object
and it accelerates 4 m/s2, what is the
mass of the object?

Answers

Answer:

The answer is 3 kg

Explanation:

The mass of the object can be found by using the formula

[tex]m = \frac{f}{a} \\ [/tex]

f is the force

a is the acceleration

From the question we have

[tex]m = \frac{12}{4} \\ [/tex]

We have the final answer as

3 kg

Hope this helps you

write an essay on the great wall of china​

Answers

The Great Wall of China is one of the greatest architectural achievements ever recorded in history. The Great Wall translates to “long fortress.” The wall was made entirely by hand. It was built to protect the Chinese from intruders from different Nomadic Tribes. The wall is about 5,500 miles long. The wall did not stretch across all of China but it stretched from Shanhaiguan in the East to Lop Nur in the West. Some people say that you can even see the wall from the moon! Wouldn’t that be something to see? The wall is very old and has been around for about 2,000 years. Parts of the wall are missing from it decaying and crumbling. Despite parts of the wall missing it remains a popular attraction today and is one of the seven spectacular…show more content…
During the Ming dynasty (1368-1644) was when much most of the wall was added. The Mind dynasty suffered from their attackers the Dadan, Nuzhen, and Tufan tribes. The Ming court built a lot more walls in the north as an attempt to keep out the attacking tribes. They built the walls much more elaborate and durable than the Qin Dynasty. There were many walls, fortresses, and watch towers along the wall which made the country more successful. Even with all the new construction on the wall the Ming dynasty was defeated by the Oirats in the battle of Tumu in the year 1449. The Ming dynasty had failed to keep the Mongolian and Manchurian tribes under control and it had weakened the Ming Empire. After the Mings loss in this battle they built more walls to make them less vulnerable if they were attacked. Towards the end of the Ming dynasty the Great Wall helped a lot to defend them from the Manchu invaders. The Manchus got into Beijing through the Shanhaiguan gates and took over the city ending the rule of the Ming dynasty and starting the new rule of the Qing Dynasty. The Qing Dynasty extended Chinas territory farther north beyond the Great Wall. The wall didn’t protect China’s border anymore so, construction on the wall stopped and soldiers abandoned their posts on the wall. The wall wasn’t used again after.
Today, the Great Wall is still standing in some parts but people fear that itthe Great Wall] demonstrates the manifestation of the wisdom and tenacity of the Chinese people.”(cortland.edu). China is considered one of the world’s oldest civilizations with the first dynasty beginning in 221 B.C.. A famous icon of this great civilization is the Great Wall of China, or known to the Chinese as Wan Li Chang Cheng. During the Warring States period, many feudal societies built their own sections for security. Eventually the walls were connected and there was a unified China. With The Great Wall of China is known as the largest construction project to be put in effect in all of world history. The wall, also known in China as "long wall of 10,000 li," is a collection of numerous short walls extending along the crest of hills on the southern edge of the Mongolian plain. Although it is a common misconception that the Great Wall of China is one long continuous wall, it 's structural inconsistency in no way undermines its greatness. The wall has been built, destructed,includes modules of ________ so you can see the construction of _____ Today I am going to be presenting the Great Wall of China and what political and military reasons it was built for. The construction was a feat of great magnitude and reflected the innovations and technological advancements of the Ancient Chinese. The reason I have decided to focus upon the Ancient Chinese is because I find China a very interesting civilisation. The ancient Chinese civilisation began 7,000 to 8,000 years ago and about
The Great Wall of China James Allen World History 1st period February 1, 2015 The first unified Chinese empire was formed in 221 B.C., that was when seven states were brought together by Shi Huangdi, a conqueror from the state of Qin. Shi Huangdi means “first emperor.” Until the twentieth century all rulers of imperial China called themselves the emperor. The emperor was believed, by the people of China, to be the son of heaven, God-like

Consider the line graph depicting the motion of two cars. What statement regarding the cars motion is accurate?

Answers

Answer:

Its C

Explanation:

I did it on usatestprep

Which statement describes the pattern in the density of gases in the

atmosphere?

A. They are least dense in the atmosphere near sea level

B. They are less dense near the top of the atmosphere

C. They are densest near the middle of the

atmosphere

D. They are every dense thoughout the attesohere

Answers

B

Because less particle are found near the top of the atmosphere

Gases are less dense near the top of the atmosphere.

What is atmosphere?

All life on Earth is shielded by the atmosphere, a layer of gases that regulates temperatures within a narrow range and deflects harmful solar rays.

The layer of gases that covers Earth is known as the atmosphere. The gravitational pull of the Earth keeps it close to the planet's surface. The three primary gases that make up the atmosphere are argon, oxygen, and nitrogen.

Density of atmosphere is high at sea level and gradually decreases with height. And at top of the atmosphere, gas is less dense.

Learn more about atmosphere here:

https://brainly.com/question/26767532

#SPJ5

What are the main differences between asexual reproduction and sexual reproduction?
Asexual reproduction requires two parents and produces non-identical offspring, while sexual reproduction requires only one parent and produces identical offspring.
Asexual reproduction requires two parents and produces identical offspring, while sexual reproduction requires only one parent and produces non-identical offspring.
Asexual reproduction requires only one parent and produces identical offspring, while sexual reproduction requires two parents and produces non-identical offspring.
Asexual reproduction requires only one parent and produces non-identical offspring, while sexual reproduction requires two parents and produces identical offspring.

Answers

Answer:

option c

Asexual reproduction requires only one parent and produces identical offspring, while sexual reproduction requires two parents and produces non-identical offspring.

Answer:

C

Explanation:

Which device consists of two separate coils of wire wrapped around an iron
ring?
O A. A transformer
B. A generator
C. A motor
D. A commutator

Answers

Answer:

It would be transformer

Explanation:

hope this helped

Answer:

transformer

Explanation:

got it right

A diver is on a board 1.80 m above
the water. She jumps straight up
at 3.62 m/s.
At what speed does she hit the water?
[?] m/s

Answers

Answer:

v = 6.95 m/s

Explanation:

Given that,

A diver is on a board 1.80 m above  the water, s = 1.8 m

The initial speed of the diver, u = 3.62 m/s

Let v is the speed with which she hit the water. It will move under the action of gravity. Using the equation of motion as follows :

[tex]v^2-u^2=2gs\\\\v=\sqrt{u^2+2gs} \\\\v=\sqrt{(3.62)^2+2(9.8)(1.8)} \\\\v=6.95\ m/s[/tex]

So, she will hit the water with a speed of 6.95 m/s.

help me, please!!!!!!

Answers

What do you need help with?

A roller coaster is stopped on a track. When the engineer presses a launch button on the coaster, the coaster moves forward. Explain this change in terms of balanced and unbalanced forces.

Answers

A roller coaster is stopped on a track. When the engineer presses a launch button on the coaster, the coaster moves forward. Explain this change in terms of balanced and unbalanced forces.

Explain why both a power source (like a battery) and a complete circuit are necessary for an electromagnet to function. 

Answers

Answer: So that it can function.

Explanation:

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