Answer: The control group is the part where you see what happens when you change a variable you want to study/examine. Basically, you need the control group because you need something to see what happens when you change something.
Hope this Helps! :))))
A woman driving a car traveling at 40 m/s slams on the brakes and decelerates at 4 m/s2. How far does the car travel before it stops?
Answer:
The car goes, x = 200 [m]
Explanation:
In order to solve this problem we must use the following kinematic equation.
[tex]v_{f} ^{2} =v_{i} ^{2} - (2*a*x)[/tex]
where:
Vf = final velocity = 0
Vi = initial velocity = 40 [m/s]
a = desacceleration = 4 [m/s^2]
x = distance traveled [m]
Note: The negative sign of the above equation indicates that the vehicle is slowing down
Now replacing:
0 = (40)^2 - (2*4*x)
(0 - 40^2) = - 8*x
x = 200 [m]
At serve, a tennis player aims to hit the ball horizontally, as shown in the figure.
(a) What minimum speed is required for the ball to clear the 0.90-m-high net about 15.0 m
from the server if the ball is “launched” from a height of 2.50 m?
(b) Where will the ball land if it just clears the net (and will it be “good” in the sense that it
lands within 7.0 m of the net)?
(d) How long will it be in the air?
(a) The minimum speed required for the ball to clear the net is 26.3 m/s.
(b) The horizontal distance of the ball when it clears the net is 11.3 m
(c) The total time spent in the air by the ball is 1 s.
Time of motion
The time of motion of the tennis ball is calculated by using the following kinematic equation as shown below;
[tex]h = h_0 + v_0_yt - \frac{1}{2} gt^2\\\\0.9 = 2.5+ 0 - \frac{1}{2} (9.8) t^2\\\\0.9 = 2.5 - 4.9t^2\\\\4.9t^2 = 1.6\\\\t^2 = \frac{1.6}{4.9} \\\\t^2 = 0.327\\\\t = \sqrt{0.327} \\\\t = 0.57 \ s[/tex]
Minimum speedThe minimum speed of the ball is calculated as follows;
[tex]v_x = \frac{X}{t} \\\\v_x = \frac{15}{0.57} \\\\v_x = 26.3 \ m/s[/tex]
Time of motion from top of the high netThe time of motion from top of the high net is calculated as follows;
[tex]t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2\times 0.9}{9.8} } \\\\t = 0.43 \ s[/tex]
Horizontal range = 0.43 x 26.3 = 11.3 m
Total time in air = 0.57 s + 0.43 s = 1.0 s
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I need help with number 7 please.
The SPEED of a car on the highway is 75 mph.
(You're correct on #6.)
Consider a line charge as your source. What is the order of your steps when applying coulomb's law. Below is a sequence of events. Place them in the order they should occur, number 1 being the first item. Select the step number from the drop down next to each item. Items to order: 1. Plug in coulomb's law. 2. Line integrate the expression. 3. Find the position vector of your field point. 4. Find the distance vector between differential source charge and field point. 5. Define your reference. 6. Find the dynamic position vector of these differential charges. 7. Carve the line in differential segments and assign each segment differential charge.
Answer:
the correct order of events is: 5 7 6 3 4 1 2
Explanation:
In this exercise, you order the events to solve the problem of the electric field created by a line of charge a line of charge
the order of events is
a) We define a reference 5
b) cut the line into segments each one is a charge differential 7
c) find the vector of the position of charges 6
d) find the point where field is calculated 3
e) find the distance between each charge point and point of interest 4
f) insert Coulomb's law 1
f) perform the integral of line 2
therefore the correct order of events is: 5 7 6 3 4 1 2
An object falls freely from rest on a planet
where the acceleration due to gravity is
29 m/s ^2
After 3.8 s, what will be its speed?
Answer in units of m/s.
Answer:
v=u+gt , initially u=0 and g acting in the direction of movement of body.
v=0+9.8×2
v=19.6m/s
Explanation:
sorry i dont have exact answer but hope this above equation will help you ....♡
Delta waves occur during
Select one:
O a. awake relaxation.
O b. Stage 1 sleep.
O c. Stages sleep.
O d. wakefulness.
The perception of an image first, followed by noticing individual pieces of the
image, can be described as:
A. sensation.
B. perceptual processing.
C. top-down processing.
D. bottom-up processing.
SUBMIT
Answer:
The answer is Top-Down processing
Explanation:
I had this question on a apex quiz and i got it correct.
when water in a brook or system of pipes flows from a wide region to a narrow region, the speed of water in the narrow region is
Answer:
more
hope this helps
plz mark brainliest
If you have a density of 100kg/L and a mass of 1000 units, tell me the following: second what is the volume
Answer:
volume is 0.1 L
Explanation:
you can use the equation density=mass/volume
100 = 1000 / v
divide by 1000 on both sides
0.1 = v
What happens to the oceans tides if the ocean if the Earth spins slower?
Answer:
As the earth rotates, it tries to drag/bring the tidal bulges with it. When a large amount of friction is applied, the earth spin will gradually and slow down but not all the way down.
Answer:
If the Earth spun slower the rate of tides will be higher because the moon will start revolving faster tan the Earth, creating more tides as the moon will revolve more around the Earth in a month.
If my answer helped, kindly mark me as the brainliest !!
Thank You!!
state and explain the changes in stability of the beaker when the water freezes to ice
Answer:
if the question is referring to what happens when ice freezes you could say that the water molecules have lass energy so they don't move around as much
What is the name of the force that acts between any two objects because of
their masses?
Answer:
Explanation:
The force of attraction between 2 masses.
A magnet is moved toward a coil or wire to induce an electric current. What will happen if the magnet is reversed and moved toward the coil of wire again? (Answer choices attached in photo)
Answer: the direction of the induced current will change :)
Explanation:
Which technology collects data for weather climate and environmental environmental monitoring from space
Answer:B) satellites
Explanation:
I just took the tests
What is the weight of a person whose mass at sea level is 72 kg ?
Answer:
158LB
Explanation:
The person's weight is equal to 705.6 N when the mass at sea level is 72 kg.
What is the weight of the object?The weight of a body can be defined as the force acting on the body due to gravity. Weight is a vector quantity if the gravitational force is working on the object.
The unit of the weight is that of force, which (S.I. unit) is Newton. A body with a mass of one Kg has a weight of 9.8 N on the surface of the Earth or on the seal level.
The mathematical equation to determine the weight of an object is written as follows:
W = mg
Given the mass of the person, m = 72 Kg
The acceleration due to gravity on the person, g = 9.8 m/s²
The weight of the person on the earth will be equal to:
W = 72 Kg × 9.8 m/s²
W = 705.6 N
Therefore, the weight of the person is 705.6 N.
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Which change(s) of state require an increase in energy?
Answer: Melting, evaporation and sublimation.
Melting, evaporation and sublimation require an increase in energy.
To determine the changes of state that require an increase in energy, we need to know about changes of state.
What are the changes of state of a substance?Melting, evaporation and sublimation are the changes of state of a substance.
How do melting, evaporation and sublimation require an increase in energy?In melting process, substance goes from solid to liquid state. In evaporation state, it goes from liquid to vapour state and in sublimation, it goes from solid to vapour state.In each of the above case, the bonds between molecules of the substance become weak due to getting of heat energy. And the heat energy is appeared as kinetic energy of the molecules.So the molecules vibrate rapidly which leads to the change of state.Thus, we can conclude that melting, evaporation and sublimation require an increase in energy.
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A ball is thrown straight upward with an initial velocity of 16m/s. What is its velocity at its highest point?
Answer:
its going very fast
Explanation:
what happens to the matter that makes up a liquid when sound travels through it
Explanation:
The matter passes in the directions of the noise and flows from the source to a receiver like sound flows through a substance. As the sound flows through a fluid, the material is disrupted for an amount of time, but after the sound leaves, it restored to its normal location.
100 POINTS HELP!!!!!!!!!!!!!
Answer:
it is whatever the temperature is at 5(I cant seem to see it clearly)
Explanation:
The equation for water is H2 +O2 - H2O. To balance the equation, which coefficient should be placed in front of H2 and H2O?
1
2
3
4
Answer:
Question: The equation for water is H2 +O2 → H2O. To balance the equation, which coefficient should be placed in front of H2 and H2O?
Answer: B.)2
Explanation:
The coefficient that would need to be placed in front of the H2, to balance the equation would be 2. After doing this all of the atoms for their respective elements will be balanced.
To balance the equation, coefficient 2 should be placed in front of H2 and H2O.
BALANCING EQUATION:
A chemical equation is said to be balanced if the number of atoms of each element on both sides of the equation are the same. According to this question, an equation that combines hydrogen and oxygen gases to form water was given as follows:H2 + O2 → H2OTo balance the above equation, we make use of coefficient 2 to ensure that the number of atoms (4) of hydrogen are the same on both sides. The balanced equation is as follows:2H2 + O2 → 2H2OLearn more at: https://brainly.com/question/21049751?referrer=searchResults
Find the velocity of the car after 6.9 s if its acceleration is 1.5 m/s² due south.
The velocity of the car after 6.9 s if its acceleration is 1.5 m/s² due south would be 10.35 meters / seconds.
What are the three equations of motion?There are three equations of motion given by Newton
v = u + at
S = ut + 1/2×a×t²
v² - u² = 2×a×s
Note that these equations are only valid for a uniform acceleration.
As given in the problem we have to find the velocity of the car we have to find the velocity of the car after 6.9 s if its acceleration is 1.5 m/s² due south,
The acceleration of the car = 1.5 m/s²
The time taken by the car = 6.9 seconds
By using the first equation of the motion,
v = u + at
v = 0 + 1.5*6.9
v = 10.35 meters / seconds
Thus, the velocity of the car after 6.9 s, if its acceleration is 1.5 m/s² due south, would be 10.35 meters / seconds.
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Evaporation of sweat requires energy and thus take excess heat away from the body. Some of the water that you drink may eventually be converted into sweat and evaporate. If you drink a 20.0-ounce bottle of water that had been in the refrigerator at 3.8 °C, how much heat is needed to convert all of that water into sweat , knowing 1ml contains 0.03 ounces? (Note: Your body temperature is 36.6 °C. For the purpose of solving this problem, assume that the thermal properties of sweat are the same as for water.)
Answer:
The amount of heat required is [tex]H_t = 1.37 *10^{6} \ J [/tex]
Explanation:
From the question we are told that
The mass of water is [tex]m_w = 20 \ ounce = 20 * 28.3495 = 5.7 *10^2 g[/tex]
The temperature of the water before drinking is [tex]T_w = 3.8 ^oC[/tex]
The temperature of the body is [tex]T_b = 36.6^oC[/tex]
Generally the amount of heat required to move the water from its former temperature to the body temperature is
[tex]H= m_w * c_w * \Delta T[/tex]
Here [tex]c_w [/tex] is the specific heat of water with value [tex]c_w = 4.18 J/g^oC [/tex]
So
[tex]H= 5.7 *10^2 * 4.18 * (36.6 - 3.8)[/tex]
=> [tex]H= 7.8 *10^{4} \ J [/tex]
Generally the no of mole of sweat present mass of water is
[tex]n = \frac{m_w}{Z_s}[/tex]
Here [tex]Z_w[/tex] is the molar mass of sweat with value
[tex]Z_w = 18.015 g/mol[/tex]
=> [tex]n = \frac{5.7 *10^2}{18.015}[/tex]
=> [tex]n = 31.6 \ moles [/tex]
Generally the heat required to vaporize the number of moles of the sweat is mathematically represented as
[tex]H_v = n * L_v[/tex]
Here [tex]L_v[/tex] is the latent heat of vaporization with value [tex]L_v = 7 *10^{3} J/mol[/tex]
=> [tex]H_v = 31.6 * 7 *10^{3} [/tex]
=> [tex]H_v = 1.29 *10^{6} \ J [/tex]
Generally the overall amount of heat energy required is
[tex]H_t = H + H_v[/tex]
=> [tex]H_t = 7.8 *10^{4} + 1.29 *10^{6}[/tex]
=> [tex]H_t = 1.37 *10^{6} \ J [/tex]
9. Juan is 32 years old. What is his maximum target heart rate?
A 186
B. 187
C. 188
D. 189
Answer:
C. 188
Explanation:
Getting the "maximum target heart rate" of a person is very easy. All you have to do is to subtract Juan's age (32) from 220.
So, 220-32 = 188
Therefore, Juan's maximum target heart rate is 188.
When exercising, it is very important not to exceed the maximum heart rate in order to prevent straining yourself. The maximum target heart rate is also being used in order to get your actual "target heart rate." This will depend on the type exercise intensity you want, whether it is moderate or vigorous.
planets A & B are near each other but there is a large difference in their temperatures using the data in the table explain how the atmosphere of these two planets can influence the average temperature
Answer: Planet A is closer to the Sun and has much greater atmospheric pressure. This suggests that planet A has a thicker atmosphere. Planet A's atmosphere is also mostly made of carbon dioxide, which is a greenhouse gas. This gas retains heat, raising the surface temperature of planet A.
Explanation:
Planet A is closer to the Sun and has much greater atmospheric pressure. This suggests that planet A has a thicker atmosphere. Planet A’s atmosphere is also mostly made of carbon dioxide (CO2), which is a greenhouse gas. This gas retains heat, raising the surface temperature of planet A.
Hope this one help.
This glass of lemonade is sitting in the hot summer sun. As time passes, in which direction will heat transfer take place?
The heat transfer takes place from the Ice to lemonade (ice → lemonade).
What is heat transfer?The term “heat transfer” refers to the movement of heat. The flow of heat across a system's boundary is due to a temperature differential between the system and its surroundings.
When a temperature difference exists between states of matter, heat transfer happens solely in the direction of decreasing temperature, that is, from a hot object to a cold item.
The temperature of ice is increasing while the lemonade is decreasing. Heat transfer happens solely in the direction of decreasing temperature,
Hence, the heat transfer takes place from the Ice to lemonade (ice → lemonade.
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Answer: C
Explanation:
increased force will increase acceleration true or false.
The amount of energy necessary to remove an electron from an atom is a quantity called the ionization energy, Ei. This energy can be measured by a technique called photoelectron spectroscopy, in which light of wavelength λ is directed at an atom, causing an electron to be ejected. The kinetic energy of the ejected electron (Ek) is measured by determining its velocity, υ (Ek= mυ2/2), and Ei is then calculated using the conservation of energy principle. That is, the energy of the incident light equals Ei plus Ek. What is the ionization energy of selenium atoms in kJ/mol if light with λ = 48.2 nm produces electrons with a velocity of 2.371x106 m/s? The mass, m, of an electron is 9.109x10-31 kg. (Round to the ones place.)
Answer:
The value is [tex]E_i = 1.5596 *10^{-18} \ J[/tex]
Explanation:
From the question we are told that
The wavelength is [tex]\lambda = 48.2 nm = 48.2 *10^{- 9 }\ m[/tex]
The velocity is [tex]v = 2.371*10^6 \ m/s[/tex]
The mass of electron is [tex]m_e = 9.109*10^{-31} \ kg[/tex]
Generally the energy of the incident light is mathematically represented as
[tex]E = \frac{h * c}{\lambda}[/tex]
Here c is the speed of light with value [tex]c = 3.0 *10^{8} \ m/s[/tex]
h is the Planck constant with value [tex]h = 6.62607015 * 10^{-34 } J\cdot s[/tex]
So
[tex]E = \frac{6.62607015 * 10^{-34 }* 3.0 *10^{8}}{48.2 *10^{- 9 }}[/tex]
=> [tex]E = 4.12 *10^{-18} \ J [/tex]
Generally the kinetic energy is mathematically represented as
[tex]E_k = \frac{1}{2} * m_e * v^2[/tex]
=> [tex]E_k = \frac{1}{2} * 9.109*10^{-31} * (2.371*10^6 )^2[/tex]
=> [tex]E_k = 2.56 *0^{-18} \ J [/tex]
Generally the ionization energy is mathematically represented as
[tex]E_i = 4.12 *10^{-18} - 2.56 *0^{-18}[/tex]
=> [tex]E_i = 1.5596 *10^{-18} \ J[/tex]
What is the elapsed time between the 0-m mark and the 40-m mark
Answer:
a) 4.0 s
b) 16 m/s
c) The distance covered between 4 - 5 s is four times the distance covered between 4 - 5 s
d) Equal distance are covered between 0 - 4 s and 4 -5 s
Note: The question is incomplete. The complete question is as follows;
Refer to the chart below that has data about a moving object to answer the following questions.
Time Elapsed 0.0s 1.0s 2.0s 3.0s 4.0s 5.0 s
Distance Traveled 0.0m 10.0m 20.0m 30.0m 40.0m 80.0 m
a. What is the elapsed time between the 0-m mark and the 40-m mark?
b. How large is the average velocity of the object for the interval from 0-5 s ?
c. How does the interval of 3-4 s compare with the interval from 4-5 s in terms of distance?
d. How does the interval of 0-4 s compare with the interval from 4-5 s in terms of distance?
Explanation:
a. From the data provide, time elapsed between the 0 m - 40 m mark is 4.0 s
b. Average velocity = total distance/ total time
average velocity = 80 m/ 5.0 s = 16.0 m/s
c. Distance covered between 3 - 4 s = 40 m - 30 m = 10 m
Distance covered between 4 - 5 s = 80 m - 40 m = 40 m
The distance covered between 4 - 5 s is four times the distance covered between 4 - 5 s
d. Distance covered between 0 - 4 s = 40 m - 0 m = 40 m
Distance covered between 4 - 5 s = 80 m - 40 m = 40 m
Equal distance are covered between 0 - 4 s and 4 -5 s
what’s the best answer , a , b , c or d
Answer:
The Basic Concept
When we look at an object at rest, we say that it is in equilibrium since all the forces being applied on it, cancel out
now, if one of the force was slightly more than the other one in the same case. The object will start to move and NOT be in equilibrium
BUT
if an object is in a vacuum and moving on a frictionless surface, the object will attain equilibrium after some seconds since it will be moving with constant speed and all the forces acting on it will be equal
Hence, if the object is accelerating. we can say with surety that the object is not is equilibrium since from the second law of motion,
F = ma ; when a is a non-zero value, there is definitely some net force being applied on the object
Looking at the given case
in the question, we are given that the object is 'accelerating' upwards
we proved above that if an object is accelerating, there is some net force on that object and hence the object is NOT in equilibrium
Since the object is accelerating, from the second law of motion:
F = ma; m cannot be zero and if a is a non-zero value as given in the question, there is definitely some net force on the object
Since there is some force being applied on the object, the object is NOT in equilibrium
Conclusion
Since we found that the object is NOT in equilibrium and that there is some net force on the object,
The first option is correct
I will give you branilest
Describe a senario that demonstartes Newtons 3rd law. Include the terms action and reaction.
Answer:
Explanation:
if you bounce a tennis ball, it will come back up as an equal reaction to your action (dropping it). there is an equal but opposite reaction in this scenario, demonstrating newton's third law.
Answer:
when u jump in the air and hit the ground the ground applies the same force back which applies a opposite force which causes u to propel into the air
Explanation:
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