A student is investigating the affect of different salts on melting points. Four patches of ice of equal
size are roped off and a
different type of salt is poured on each, one receives table salt (NaCl), one
receives Calcium Chloride (CaCl2), one receives Potassium Carbonate (KCO3) and the fourth
receives inert sand instead. Each patch receivęs an equal amount of salt or sand. The student
measures the volume of ice remaining and subtracts it from the original volume of ice to see how
much melted away. What is a control variable in this experiment?
A. The size of the ice patches.
B. The type of salt applied to the ice.
C. The amount of ice that melted.
D. None of these.
Answers
Answer:
A. The size of the ice patches
Explanation:
In an experiment, the control variable also known as the CONSTANT is the variable that must be kept uniform or the same for all groups throughout the experiment in order not to influence the outcome of the experiment.
According to the experiment described in this question, the effect of different salts on melting points is investigated by a student. Sodium chloride (NaCl), Calcium Chloride (CaCl2), Potassium Carbonate (KCO3) and inert sand are the four types of salt used. The volume of the ice used and melted was finally measured. This means that the SIZE OF THE ICE PATCHES USED is the control variable of the experiment as the same size was used for all groups throughout.
Answer:
the size of the ice patches
Explanation:
Related Questions
Which of the following quantity is unit-less? 1 Specific gravity 2 Mass density 3 Acceleration due to gravity 4 All of the above
Answers
Answer:
1
Explanation:
Specific gravity is a ratio (of 2 densities) so it has no unit.
It is easier to lift the same load by using three pulley system than by using two-pulley system. why give reason.
Answers
Logic behind is lies behind the mechanical advantage of the provided bt the Pulley system.
as if we calculate the mechanical advantage of the 2 Pulley system we will have the value 2
And if we will calculate the mechanical advantage of the 3 pulley system then we will get the value of 3
so due to extra mechanical advantage we feel it easy to move with 3 pulley system then 2 Pulley system
[tex] \red \star{Thanks \: And \: Brainlist} \blue\star \\ \green\star If \: U \: Liked \: My \: Answer \purple \star[/tex]
why is fundamental unit called derived unit ?
Answers
Since fundamental units are elementary in nature and cannot be reduced further, so it can not be reduced further, so it cannot be expressed in other units
A neutral object must have _______________ A. An equal amount of positive and negative charges B. no charges present at all C. more positive than negative charges D. more negative than positive
Answers
Answer:
A
Explanation:
Consider a question you may not have considered before. Suppose you have a mole of sodium in a container that contains nothing that it will react with. A mole of anything is 6.02 * 10^23 (in this case atoms).
Suppose that every one of those atoms has contributed 1 electron to something.
Do you think it would be safe to touch the container knowing that there are 6.02 * 10^23 positive charges all eager to get another electron, because they don't like repelling each other.
Safe or not? I'll give you a hint. A lightning bolt does not contain anywhere near 6.02*10^23 charges. No where near.
So -- since you never get a shock from just touching anything, There must not be electrons or ions present.
The answer is A
What is the relationship between Avogadro's number and a mole?
A. There are 6.02 x 1023 items in a mole, which equals Avogadro's
number
B. A mole is a smaller amount than Avogadro's number.
C. Avogadro's number is used to count particles, and a mole is used
to measure mass.
D. A mole applies to any item, but Avogadro's number is limited to
atoms.
SUBM
Answers
Answer:
A. There are 6.02 x 1023 items in a mole, which equals Avogadro's
number
Explanation:
The mole of a substance is
Having the correct posture and the degree or severity of braking, acceleration and steering inputs have a direct result on the ability of a motorist to effectively address changes in __________?
Answers
Answer: Vehicle Balance
Explanation:
Vehicle balance simply means how the weight of a vehicle is distributed across its tires which connects to the road
It should be noted that there'll be a shift in the balance of a vehicle when the braking, acceleration, or turning bring about a scenario in which the weight of th vehicle moves from one area to another.
Please answer will mark brainleist
Answers
[tex]option \: (a) \: is \: correct.[/tex]
Explanation:
Yes, I was wrong. Pressure increases as the area decreases.
As per the Figure A, the truck is so heavy and having a greater mass. So, the area of contact between the tyres and the road increases and decreases it's pressure on the road due to the increase in area.
As per the Figure B, You know the nature of Tomato that it is soft and smooth to touch and also lighter mass when it's compared with the truck. As it having a lighter mass, it can be cut through the sharp knife. The area of contact decreases and pressure increases on the vegetables.
Answer:
Option number B
Explanation:
The pressure is indirectly proportional to the area therefore pressure decreases when the area increases, and pressure increases when the area decreases
if the volume of cylinder is 1000 cm with 14cm height. Then find the radius of cylinder
Answers
Answer:
radius=4.77cm
Explanation:
given
r=? ,h=14 , v=1000
then using the formula
[tex]r = \sqrt{ \frac{v}{\pi \: h} } [/tex]
= √1000/π•14
=4.77cm
What is the dependent variable in this
experiment?
DONE
Biologists designed an experiment to test
the effect of compost on the development
of root crops. They tested several different
crops, including carrots, potatoes, beets,
and onions. They grew most of the plants
in the greenhouse, but due to space issues,
they had to grow some outdoors. They gave
all the plants the same amount of compost.
They obtained the compost from a local
farmer and from the local hardware store.
They ran out of the farmer's compost, so
some of the plants received that compost
when the seeds were planted and other
plants got hardware store compost after
the plants had already started growing.
What is the independent variable in this
experiment?
DONE
Answers
Answer:
"the plants had already started growing."
Explanation:
I think this is the answer because the definition of a dependent variable is the variable that is being affected by the change. Since the plants had already started growing BECAUSE of "They ran out of the farmer's compost, so
some of the plants received that compost
when the seeds were planted and other
plants got hardware store compost after
the plants had already started growing."
Sorry if I am wrong, I am just a 4th grader, pls don't hate on me, I am just trying to help :)
Answer:
It's compost
Explanation:
In case you needed the dependent variable, its the amount of plant growth
A penny is dropped into a well. It takes 5 seconds to fall. Calculate the depth of the well in feet.
Answers
Answer:
d=1/2 (a)(t^2)
D = distance
A = acceleration
T = time
acceleration due to gravity is 32 ft/second
so, d=1/2 (32)(5^2)
d=16(25)
d=400
Explanation:
Answer:
400 ft.
Explanation:
D= 1/2 gt^2
=1/2(-32 ft/sec^2)(5 sec^2)
= -(1/2)(32)(25) ft
D= -400 ft, down
According to the principle that the emission lines of a substance must be at exact same positions of its absorption spectrum, what substance accounts for the dark lines in the absorption spectrum
Answers
Answer:
The dark lines in absorption spectrum of light is due capacity of atoms to absorb light of a specific energy. The absorption of light by atoms occurs when the atom transitions from a lower energy or ground state to an excited high energy state, and it appears in the emission spectrum of the element as dark lines located in the same position as the bright lines
Explanation:
If displacement has a magnitude AND direction is it a scalar or vector quantity?
scalar
vector
Answers
Explanation:
Obviously vector quantity
why is oil denser than air
Answers
Answer:
The molecules of oil are more packed together than those of air.
A uniform meter rule of mass 10g is balanced on a knife edge placed at 45cm mark. Calculate the distance of a mass 25g from the pivot
Answers
Answer:
2 cm.
Explanation:
Please see attached photo for diagram.
In the attached photo, y is the distance from the pivot to which the 25 g is placed.
The value of y can be obtained as follow:
Clockwise moment = 5 × 10
Anticlock wise moment = y × 25
Anticlock wise moment = Clockwise moment
y × 25 = 5 × 10
y × 25 = 50
Divide both side by 25
y = 50/25
y = 2 cm
Thus, the distance is 2 cm
The electric motor in the car is powered by a battery.
To charge the battery, the car is plugged into the mains supply at 230 V
The power used to charge the battery is 6.9 kW
Calculate the current used to charge the battery.
Answers
Answer:
I = 30 A.
Explanation:
Given that,
The voltage of the battery, V = 230 V
Power used to charge the battery, P = 6.9 kW
We need to find the current used to charge the battery. The formula for the power is given by :
P = VI
Where
I is current
So,
So, the required current is 30 A.
A cylindrical container closed of both end has a radius of 7cm and height of 6cm A.)find the total surface area of the container B.) find the volume of the container
Answers
Answer: TSA = 572 cm^2
Volume = 924 cm^3
TSA of a cylinder = 2πr^2+2πrh
= 2πr(r+h)
= 2×22/7×7(7+6)
= 44×13
= 572 cm^2
Volume of the container= V = πr^2 h
= 22/7 * 7*7 * 6
= 924 cm^3
What information does the period number give about an atom?
Answers
Answer:All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.Explanation:
Answer:
It tells us the principle quantum shell in which the element lies in. In other words, it shows the total number of electron shells the atom has
4. An object is thrown from from the ground upward with an initial speed of 3.75 m/s. How long will the object be in the air before it lands on the ground?
Answers
Answer:
Explanation:
There's an easy way to answer this and then an easier way. I'll do both since I'm not sure what you're doing this for: physics or calculus. Calculus is the easier way, btw.
Going with the physics version first, here's what we know:
a = -9.8 m/s/s
v₀ = 3.75 m/s
t = ??
That's not a whole lot...at least not enough to directly solve the problem. What we have to remember here is that at the max height of a parabolic path, the final velocity is 0. So we can add that to our info:
v = 0 m/s. Use the one-dimensional equation that utilizes all that info and allows us to solve for time:
v = v₀ +at and filling in:
0 = 3.75 + (-9.8)t and
-3.75 = -9.8t so
t = .38 seconds. This is how long it takes to get to its max height. Another thing we need to remember (which is why calculus is so much easier!) is that at the halfway point of a parabolic path (the max height), the object has traveled half the time it takes to make the whole trip. In other words, if .38 is how long it takes to go halfway, then 2(.38) is how long the whole trip takes:
2(.38) = .76 seconds. Now onto the calculus way:
The position function is
[tex]s(t)=-4.9t^2+3.75t[/tex] The first derivative of this is the velocity function and, knowing that when the velocity is 0, the time is halfway gone, we will find the velocity function and then set it equal to 0 and solve for t:
v(t) = -9.8t + 3.75 and
0 = -9.8t + 3.75 and
-3.75 = -9.8t so
t = ,38 and multiply that by 2 to find the time the whole trip took:
2(.38) = .76 seconds.
Se lanza una pelota de béisbol desde la azotea de un edificio de 25 m de altura con velocidad inicial de magnitud 10 m/s y dirigida con un ángulo de 63.1° sobre la horizontal. A) ¿Qué rapidez tiene la pelota justo antes de tocar el suelo? Use métodos de energía y desprecie la resistencia del aire.
Answers
Answer:
v_f = 24.3 m / s
Explanation:
A) In this exercise there is no friction so energy is conserved.
Starting point. On the roof of the building
Em₀ = K + U = ½ m v₀² + m g y₀
Final point. On the floor
Em_f = K = ½ m v_f²
Emo = Em_g
½ m v₀² + m g y₀ = ½ m v_f²
v_f² = v₀² + 2 g y₀
let's calculate
v_f = √(10² + 2 9.8 25)
v_f = 24.3 m / s
A car travelling at 10ms ,acceleration uniformly at 2ms what will be its velocity after 5s?
Answers
[tex]we \: know \: that \\ acceleration = \frac{(final \: velocity - initial \: velocity)}{time} \\ = > a = \frac{(v - u)}{t} \\ = > 2m {s}^{ - 2} = \frac{{(v - 10m {s}^{ - 1} })}{5s} \\ = > 2m {s}^{ - 2} \times 5s = v - 10m {s}^{ - 1} \\ = > 10m {s}^{ - 1} = v - 10m {s}^{ - 1} \\ = > 10m {s}^{ - 1} + 10m {s}^{ - 1} = v \\ = > 20m {s}^{ - 1} = v \\ = > 20m {s}^{ - 1} = initial \: velocity[/tex]
Hope it helps!!
Thanks!!
Answer:
20 ms
Explanation:
You know
acceleration=2ms initial Velocity=10ms Time=5s
We are finding Final V
Use the equation Final v = (a x t) + initial v
2 x 5 = 10
10 + 10 = 20
Help me and I'll make u Brainliest and follow u
Answers
26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
the bodies in this universe attract one another name the scientist who propounded this statement
Answers
Answer: The scientist named Isaac Newton proposed this universal law of gravitation.
It is given that the bodies in this universe attract one another.
It is required to name the scientist who propounded this statement.
What is the name of the scientist who propounded this statement?According to Newton's law of gravitation, every object in the universe attracts every other object with a force that is proportional to the multiplication of the masses and inversely proportional to the square of the distance between the objects. This is the universal law that means this is a constant term that can't be changed with respect to place which was proposed by Isaac Newton in 1687.
Therefore, Isaac Newton proposed this universal law of gravitation.
Learn more about gravitation here:
https://brainly.com/question/12528243
#SPJ5
the electric charge remains at rest in a. static electricity, b. current electricity, c. none of these
Answers
Answer:
Option (a) is correct.
Explanation:
The electric charge is the inherent property of matter which appears due to the deficiency of charge or the excess number of electrons.
There are two types of charges, positive and negative.
When an object has deficiency of charge it becomes positive charge and when it gains some electrons, it becomes negative charge.
When the charge is in motion, it is called electric current and when the charge is at rest, it is called static current.
A charge at rest contributes the electric field only while the charge is in motion contributes the electric and magnetic field both.
why is the value of g more in terai than in the mountain
Answers
The solution and answer are well written in the Pic above.
18.How much momentum will a dump-bell of mass 10 kg transfer to the floor if it falls from a height.of 80 cm ? Take its downward acceleration to be 10 m s-2
Answers
Such asSuch ToSuch aSuch as طHow do I send the answer to the question?OkI don't know how to use this program
Answer:
MOMENTUM = 40kg ms-¹
hope it helps
have a nice day
. What is a normal force? It acts against an object slowing it down. It acts perpendicular to an object. It acts with an object adding to its speed. It acts parallel to an object.
Answers
Answer:
Explanation:
This is basically asking you what the definition of Normal force is. Normal force is the force that pushes back against the weight of something that is sitting (or standing or lying) perpendicular to it. That's why, when you stand on a floor you don't crash through the floor OR go shooting up into space. The Normal force is equal but opposite to your weight. The floor exerts the normal force (pushing up and is positive) while your weight is opposing it (pushing down and is negative.) Perpendicular is the key word here, I believe.
A normal force acts perpendicular to an object. It is the force exerted by a surface to support the weight of an object resting on it.
The normal force acting against an object slowing it down or acting with an object adding to its speed, are not accurate descriptions of the normal force. The normal force primarily deals with the support of an object on a surface and is directed perpendicular to that surface.
Normal force is the force that pushes back against the weight of something that is sitting (or standing or lying) perpendicular to it. That's why, when you stand on a floor you don't crash through the floor OR go shooting up into space. The Normal force is equal but opposite to your weight. The floor exerts the normal force (pushing up and is positive) while your weight is opposing it (pushing down and is negative.)
Therefore, A normal force acts perpendicular to an object. It is the force exerted by a surface to support the weight of an object resting on it.
To know more about the normal force:
https://brainly.com/question/13622356
#SPJ3
If a car drives 10 mph South, this is an example of a:
A. Displacement
B. Velocity
C. Distance
D. Speed
Answers
If a car drives 10 mph South, this is an example of a:
If a car drives 10 mph South, this is an example of a: Displacement
[DISPLACEMENT IS THE SHORT DISTANCE TRAVELLED BY A BODY AT A CERTAIN DIRECTION]
A velocity would be an automobile traveling south at 10 mph. Option B is correct.
What is velocity?The change of displacement with respect to time is defined as velocity. velocity is a vector quantity. It is a time-based component. Its unit is m/sec.
If the direction is given quantity is a vector quantity. In the given data the direction is given, that's why a car drives 10 mph South, this is an example of a velocity.
Hence, option B is correct.
To learn more about the velocity, refer to the link: https://brainly.com/question/862972
#SPJ2
how does a resistor affect an electrical circuit
Answers
Answer:
A resistor has the ability to reduce voltage and current when used in a circuit. The main function of a resistor is to limit current flow.
Explanation:
I this what you were looking for?
An acceleration of 2m/s^2 is produced on a body by applying an effort of 50N. calculate mass of the body
Answers
Answer:
25 kg
Explanation:
Given,
Acceleration ( a ) = 2 m/s^2
Force ( F ) = 50 N
To find : Mass ( m ) = ?
Formula : -
F = ma
m = F / a
= 50 / 2
m = 25 kg
So, the mass of the body is 25 kg.
Your force = 50 Newton’s and your acceleration = 2 meters per second
So the equation should look like this
A boy travels 12km east wards to a point B and then 5km southwards to another point C. Calculate the difference between the magnitude of the displacement of the boy and the distance travelled by him.
Answers
Explanation:
pls mark me as brainliest
If a boy travels 12 km eastwards to a point B and then 5km southwards to another point C, then the difference between the magnitude of the displacement of the boy and the distance traveled by him would be 4 kilometers.
What is displacement?An object's position changes if it moves in relation to a reference frame, such as when a passenger moves to the back of an airplane or a professor moves to the right in relation to a whiteboard. Displacement describes this shift in location.
As given in the problem a boy travels 12km eastwards to a point B and then 5km southwards to another point C.
Distance traveled = 12 + 5 = 17 km
The displacement = √ ( 12² + 5² )
= 13 km
Thus, If a boy travels 12 km eastwards to a point B and then 5km southwards to another point C, then the difference between the magnitude of the displacement of the boy and the distance traveled by him would be 4 kilometers.
To learn more about displacement here, refer to the link given below;
https://brainly.com/question/10919017
#SPJ2
