Answer:
1/2 hours
Explanation:
The formula for speed is given as;
s= d/ t -----where
s is speed , 80 km/h
d is distance , 40 km
t is time = ?
Making t is subject of the formula;
t= d/s
Using the values given
t= 40 / 80
t= 1/2 hours
What is the difference between a unit and a variable?
Explanation:
a variable In algebra, a symbol (usually a letter) standing in for an unknown numerical value in an equation.
a unit In math, the word unit can be defined as the rightmost position in a number or the one's place
Please help. I will mark you as brainliest !!!
You place a book on top of a spring and push down, compressing the spring by 10 cm. When you let go of the book, it is pushed up by the spring. Which statement describes what happens to the energy of the spring book system?
A. The elastic potential energy of the system increases.
B. The gravitational potential energy of the system increases.
C. The kinetic energy of the system decreases.
D. The total energy of the system increases.
Answer:
Eliminate D as there is no nonconservative force, then look at each energies before and after. The speed of the book will increase, so kinetic energy is increasing. The height of the book is increasing, so gravitational potential energy is increasing. However, since the spring is becoming decompressed, the elastic potential energy is decreasing.
Explanation:
Answer:
it is A
Explanation:
PLEASE HELP
OPTIONS:
Bar one:
Constant acceleration
Constant velocity
Positive acceleration
Bar two:
Remains stationary
Slows down
Speeds up
Bar three:
Constant acceleration
Constant velocity
Positive acceleration
Answer:
bar one:constant acceleration
bar two:remains stationary
bar three:constant acceleration
Help me on question 4 pls I’m giving out brainlest!!
Which statement describes the relationship between bond strength and the
melting and boiling points of a substance?
A. Substances held together by hydrogen bonding have lower melting
and boiling points than those held together by Van der Waals
forces.
B. Substances held together by ionic bonding have higher melting
and boiling points than those held together by hydrogen bonding.
C. Substances held together by Van der Waals forces have higher
melting and boiling points than those held together by ionic
bonding
O D. Substances held together by ionic bonding have lower melting and
boiling points than those held together by hydrogen bonding.
SUB
Answer: Wrong
Explanation:
The statement that accurately describes the relationship between bond strength and the melting and boiling points of a substance is; "substances held together by ionic bonding have higher melting and boiling points than those held together by hydrogen bonding."
Intermolecular forces refers to forces of attraction that holds molecules together in a particular state of matter. The nature and magnitude of intermolecular forces impacts on the magnitude of the melting and boiling points of substances.
Substances held together by ionic bonding have higher melting and boiling points than those held together by hydrogen bonding. The bonds between ionic substances can only be broken at very high temperature.
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help its science
The average kinetic energy for atoms or molecules in a substance is called __________.
Group of answer choices
temperature
volume
heat
which describes a function of the thalamus?
Answer: The primary function of the thalamus is to relay motor and sensory signals to cerebral cortex It also regulates sleep, alertness, and wakefulness.
Explanation:
The primary function of the thalamus is to relay motor and sensory signals to cerebral cortex It also regulates sleep, alertness, and wakefulness.
The shortstop plays between first and second base.
true or false
SINGLE TO RIGHT OR CENTER FIELD-On a single to center or right field the first baseman will be the cutoff to home. The shortstop will cover second base.
this is life science
What is the difference between professional and casual communication styles?
Answer:
professional communication style is expected to be formal while the casual is informal.
Explanation:
7. Two people are pushing a 40.0kg table across the floor. Person 1 pushes with a force of 490N
[W], and person 2 pushes with a force of 565N (N). If the coefficient of kinetic friction between
the table and the floor is 0.613, determine the acceleration of the table.(12.7m/s2 [49.1° Nofw])
Answer:
20.4 [tex]m/s^{2}[/tex]
Explanation:
To start doing this problem, first draw a free body diagram of the table. My teacher always tells us to do this, and I find that it is very helpful. I have attached a free body diagram to this answer- take a look at it.
First, let us see if Net force = MA. To do that, we need to determine whether the object is at equilibrium horizontally. For an object to be at equilibrium, it either needs to be moving at a constant velocity or not moving at all. Also, if an object is at equilibrium, there will not be any acceleration. But we know that there IS acceleration horizontally, so it cannot be in equilibrium. If it is not in equilibrium, we can use the formula ∑F= ma.
Let us determine the net force. Since the object is moving horizontally, we can ignore the weight and normal force, because they are vertical forces. The only horizontal forces we need to worry about are the applied force and force of friction.
Applied force = 1055 N (490 + 565)
Friction force= Unknown
To find the friction force, use the kinetic friction formula, Friction = μkN
μk is the coefficient, which the problem includes- it is 0.613.
N is the normal force, which we have to find.
*To find the normal force, we have to determine if the object is at equilibrium VERTICALLY. Since it has no acceleration vertically (it's not moving up/down), it is at equilibrium. Now, when an object is at equilibrium in one direction, it means that all the forces in that direction are equal. What are our vertical forces? Weight (mg) and Normal force (N). So it means that the Normal force is equal to the Weight.
Weight = mg = (40)(9.8) = 392 N
Normal force = 392 N
Now, plug it back into the formula (μkN): (0.613)(392) = 240.296 N
Friction = 240.296 N
Now that we know the friction, we can find the horizontal net force. Just subtract the friction force, 240.296 from the applied force, 1055 N
Horizontal Net Force: 814.704 N
Now that we know the net force, plug in the numbers for the formula
∑F= ma.
814.704 = (40.0)(a)
*Divide on both sides)
a = 20.3676 m/s^2
Round it to 3 significant figures, to get:
20.4 [tex]m/s^{2}[/tex]
Imagine that person B is more massive than person A in the picture above.
If they push off of each other with the same amount of force, who will
have the greater acceleration? What law are you applying? Explain how
that law is being applied.
The speed you read on a speedometer is ____.
Answer:
[tex]\leq 40[/tex]
Explanation:
So if you’re going 40mph, your speedometer may read up to 50.25mph - but it can never read less than 40mph. In order to stay within the law, carmakers calibrate their speedometers to slightly overreport their vehicles' speeds.
current is a ______ quantity.
scalar or vector
Answer:
vector quantity............
Explanation:
Mark me braimlist
Answer:
scalar
Explanation:
Which of the following would be considered an exercise program?
a
basketball
b
football
c
aqua dynamics
d
soccer
Answer:
c
Explanation:
What is the energy transformation that takes place when a jumbo-tron video screen shows an instant replay? A. electrical to light B. mechanical to electrical C. light to chemical D. thermal to sound
Answer:
A. electrical to light
Explanation:
A jumbo-tron video is a very large television that is most times fitted into walls and displayed along the main roads. It has a light-emitting display(LED) property. Energy transformation is the conversion of energy from one form to another.
The video screen just as a regular television in the house emits light, sound and heat energies. Electrical energy which flows from one end to another powers the jumbo-tron video screen and is thus converted into light, heat and sound energies.
The energy transformation that takes place when a jumbo-tron video screen shows an instant replay is electrical to light energy.
Energy transformation is the conversion of energy from one form to another.
A jumbo-tron video is an electrical appliance that requires electricity to power on. When jumbo-tron video screen shows an instant replay, this shows that the jumbo-tron has been powered on using electricity and converted to light displayed by the video screen.Hence the energy transformation that takes place when a jumbo-tron video screen shows an instant replay is electrical to light energy.
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Define reference point
plz help me
Answer:
a basis or standard for evaluation, assessment, or comparison; a criterion.
Explanation:
Definition of reference point. : something that is used to judge or understand something else The professor used the study as a reference point for evaluating and discussing other theories.
Answer:
something that is used to judge or understand something else
Explanation:
The professor used the study as a reference point for evaluating and discussing other theories.
What is one of the forms of a gene called?
allele
dominant
heterozygous
recessive
Answer:
Explanation:
.
Answer:
alleles
my answee need to be at least 20 characters long :(
Is visible light a form of
radiation? Explain.
Answer:
Yes,in fact visible 'light' is a form of radiation, which can be defined as an energy that travels in the form of electromagnetic waves. It can also be described as a flow of particle-like 'wave-packets', called photons, that travel constantly at the speed of light (about 300 000 kilometres per second).
Explanation:
Sam is moving house and is carrying a 300N box of books up a flight of steps 5m high, it takes her 30 seconds. Gary follows her carrying a bag of clothes doing 1000 J of work; it only takes him 25 seconds. Who provides the biggest power? Show your working.
Answer:
Sam is providing the biggest power i.e. 50 W
Explanation:
Sam is moving house and is carrying a 300N box of books up a flight of steps 5m high, it takes her 30 seconds.
Sam's power :
[tex]P_1=\dfrac{W_1}{t_1}\\\\P_1=\dfrac{F_1d}{t_1}\\\\P_1=\dfrac{300\times 5}{30}\\\\P_1=50\ W[/tex]
Gary follows her carrying a bag of clothes doing 1000 J of work; it only takes him 25 seconds.
Gary's power :
[tex]P_2=\dfrac{W_2}{t_2}\\\\P_2=\dfrac{1000}{25}\\\\P_2=40\ W[/tex]
So, it is clear that Sam is providing the biggest power.
6. What charge is in the nucleus?
a. negative charge
b. positive charge
C. no charge
d. positive and negative charges
20
Select the correct answer.
Which of these factors will increase the speed of a sound wave in the air?
A. slowing down the movement of particles in the air
OB. raising the temperature of the air
C.
removing particles form the air
D. decreasing the kinetic energy of the air
OE.
stopping particle collisions in the air
Reset
Next
Answer:
B. raising the temperature of the air
Nuclear Physicist or Scientist (It doesn't really matter)
Describe the properties of waves that make the technology that a Nuclear Physicist or Scitenist uses possible. If you have chosen a research career, what topics are the researchers interested in learning more about? Some properties you can discuss include: transverse or longitudinal, wavelength, frequency, amplitude, travels through a vacuum or does not
Thank you!
Answer:
Radio waves
Explanation:
how many days are in a calendar?
Answer:
365
Explanation:
A calendar is equal to a year and it is 365 days in a year.
Which diagram shows a situation that would not produce an electric current in the wire?
Answer:B
Explanation:
A P E X
The diagram in which there is no current in the electric wire is B, the reason behind that it is not connected with the battery.
What is Electrical energy?When put in an electromagnetic field, charged matter experiences a force due to the fundamental property of electric charge. Positive or negative electrical ions are possible.
When two charge are in opposition to one another, they repel one another. The term "neutral" refers to an object has no net charge. The early understanding of the way charged particles interact is now referred to as classical electrodynamics, and it is still true for issues that do not demand for taking into account quant phenomena.
Electrical charge is a preserved attribute, meaning that the net charged of an isolated system—that is, the sum of the positive and negative charges—cannot change. Particles at the subatomic level carry an electric charge.
The second diagram from the option will have no current in it because the wires are not connected with the battery, so the flow of current will not take place.
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What type of image is formed by a lens if m= 3.2?
A. One that is smaller than the object and virtual
B. One that is larger than the object and real
C. One that is larger than the object and virtual D. One that is smaller than the object and real
Answer:
c
Explanation:
Which best explains why trees are considered a renewable resource? O They are useful to humans. O They can be replanted. 0 They provide a source of food. They are used to produce heat.
Answer:
They can be replanted.
Explanation:
Renewable sources can be found again and again, similar to how you can plant a tree again to receive food sources and heat production, which in turn is useful to humans.
When The trees are considered a renewable resource because They can be replanted. The correct option is 'B'.
What is a Renewable Resource?
When Renewable sources can be found, again and again, similar to how you can plant a tree again to receive food sources and also heat production, they are in turn useful to humans.
When the renewable resources are resources, generally naturally happening, they can replenish to the rate that they can return the used volume and also be swallowed.
A renewable resource will either produce itself naturally through automatic approaches to that resource or through human interaction and guidance.
Therefore, The correct option is 'B'.
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Shawn is doing drills out on the field by pulling a tire behind him for 30 m. If Shawn is applying a net force of
1200 N to pull the tire, then how much work is Shawn doing?
Answer:
The work done by Shawn in moving the tire is 36,000 J
Explanation:
Given;
net force applied by Shawn , F = 1200 N
distance he moved the tire, d = 30 m
The work done by Shawn in moving the tire is calculated as;
W = Fd
Substitute the given values and solve for Work done;
W = 1200 x 30
W = 36,000 J
Therefore, the work done by Shawn in moving the tire is 36,000 J
An atom of element X has one more
shell of electrons than an atom of
calcium, but it has one less valence
electron than calcium. Which element
is element X?
Answer:
Rubidium or Rb
Explanation:
Use the periodic table, the period numbers are number of shells while the group numbers are numbers of valence electrons
Are all forms of radiation safe for humans?
Answer:
there are not all safe for humans