A student said,Today, giraffes have long necks that allow them to eat leaves high in trees. They got longer necks by stretching up for even higher leaves. After many generations, the giraffe’s neck was really long.Do you think the student’s explanation for how the giraffe’s neck became long is correct? Explain.
Answer:
yes because there is also a theory about this I studied in biology
theory name -Lamarck's theory
A 56.6-kg crate rests on a level floor at a shipping dock. The coefficients of static and kinetic friction are 0.517 and 0.260, respectively. What horizontal pushing force is required to (a) just start the crate moving and (b) slide the crate across the dock at a constant speed
Answer:
Explanation:
Magnitude of frictional force = μ mg
μ is either static or kinetic friction.
To start the crate moving , static friction is calculated .
a ) To start crate moving , force required = μ mg where μ is coefficient of static friction .
force required =.517 x 56.6 x 9.8 = 286.76 N .
b ) to slide the crate across the dock at a constant speed , force required
= μ mg where μ is coefficient of kinetic friction , where μ is kinetic friction
= .26 x 56.6 x 9.8 = 144.21 N .
A table is moved using 60 N of force.
How far is the table moved if 900 J of work is done on the table?
960 m
840 m
15 m
0.06 m
Answer:
15m
Explanation:
W=f×s
[tex]s = \frac{w}{f} \\ s = \frac{900j}{60n} \\ s = 15m [/tex]
Given:
Force,
F = 60 NWork done,
W = 900 JWe know,
→ [tex]W = F\times s[/tex]
or,
→ [tex]s = \frac{W}{F}[/tex]
By putting the values, we get
[tex]= \frac{900}{60}[/tex]
[tex]= 15 \ m[/tex]
Thus the above response i.e., "Option c" is right.
Learn more about work done here:
https://brainly.com/question/8625856
What would make oppositely charged objects attract each other more?
increasing the positive charge of the positively charged object and increasing the negative charge of the
negatively charged object
decreasing the positive charge of the positively charged object and decreasing the negative charge of the
negatively charged object
increasing the distance between the positively charged object and the negatively charged object
maintaining the distance
tance between the positively charged object and the negatively charged object
Hurry I need answers quick I’m timed
Answer:
A). Increasing the positive charge of the positively charged object and increasing the negative charge of the negatively charged object.
Explanation:
The two objects possessing opposite or unlike charges attract one another due to the electromagnetic force between the electrons, as well as, protons in order to develop ionic lattices.
As per the question, the objects having unlike charges would attract one another more when we 'escalate the positive charge of the object having a positive charge and enhance the negative charge of the object possessing negative charge.' This will lead the atoms that are losing electrons to be positively(+ve) charged and the atoms gaining electrons to be negatively
(-ve) charged. Thus, the electromagnetic force among them increases and a stronger ionic network develops leading them to attract each other more. Hence, option A is the correct answer.
Answer:
The person above me is wrong the answer is actually B
Explanation:
I put his/her answer and got it wrong and it showed me theat the answer is b not a
Describe how to determine the thickness of a sheet of a paper without a caliper.
Answer:
Divide the total measurement of the stack/ream of paper by the number of sheets. For example: 2 inches/100 pages = 0.01-inches sheets.
In case you measured the stack, and it gave you less than an inch, then you need to do the same. For example: 0.5-inches/100 sheets = 0.005-inches per sheet.
Answer:
Divide the total measurement of the stack/ream of paper by the number of sheets. For example: 2 inches/100 pages = 0.01-inches sheets.
In case you measured the stack, and it gave you less than an inch, then you need to do the same. For example: 0.5-inches/100 sheets = 0.005-inches per sheet.
Explanation:
A charge Q acts on a point charge to create an electric field. Its strength, measured a distance of 40 cm away is 100 N/C. What is the magnitude of the electric field strength at a distance of 20 cm
Answer:
[tex]E_2=80N/C[/tex]
Explanation:
From the question we are told that:
Initial Distance [tex]d_1=40cm=>0.4m[/tex]
Initial Electric field strength [tex]E_1=100N/C[/tex]
Final Distance [tex]d_2=20cm=>0.20m[/tex]
Generally the equation for Electric field is mathematically given by.
[tex]E=\frac{kq}{d^2}[/tex]
[tex]q=\frac{100*(0.4)^2}{K}[/tex]
Substituting q for [tex]d=20cm[/tex]
[tex]E_2=\frac{k}{0.2}*\frac{100*(0.4)^2}{K}[/tex]
[tex]E_2=80N/C[/tex]
The force of ____________ exists between any two objects that have mass.
free fall
acceleration
weight
gravity
Answer:
gravity
Explanation:
A 15-watt bulb is connected to a circuit that has a total of 60. Ω of resistance. How many electrons are passing through that bulb every second?
Answer:
3.2075*10^16
Explanation:
Q=P/V just search up a converter and youll get 30V and so you do 15/30 which is a half and a single coulomb is 6.415*10^16 so you half it. I belive this is correct if you dont belive me wait for someone else smarter to answer and compare.
What would happen to the distance between the bright fringes produced by a diffraction grating if the entire interference apparatus (light source, grating, and screen) were immersed in water
Answer:
Since the wavelength would be reduced by the factor of N where N is the index of refraction, fringes would be be closer to one another.
(Similar to the difference of fringes of red light and blue light.)
Mark was traveling at 40 mph on a road with a drag factor of 0.85. His brakes were working at B0o/o efficiency. To the nearest tenth of a foot, what would you expect the average length of the skid marks to be if he applied his brakes in order to come to an immediate stop
The average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is 78.43 ft.
The given parameters:
Speed of Mark, v = 40 mphDrag factor, F = 0.85Working efficiency of the brake, n = 80%The average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is calculated as follows;
[tex]v = \sqrt{30 D fn} \\\\40 = \sqrt{30 \times D \times 0.85 \times 0.8} \\\\40 = \sqrt{20.4 D} \\\\40^2 = 20.4D\\\\1600 = 20.4 D\\\\D = \frac{1600}{20.4} \\\\D = 78.43 \ ft[/tex]
Thus, the average length of the skid marks to be if he applied his brakes in order to come to an immediate stop is 78.43 ft.
Learn more about length of a skid mark here: https://brainly.com/question/16914218
Pop up spring Lab
Describe the energy conversion that took place. What energy was present just before the jump? What energy is present at its maximum height? What happens in between?
Draw bar charts of energy before the jump, while the spring toy is compressed and after the jump at the maximum height of its jump. Be sure to label each type of energy.
Answer:
I honestly don't know but that thing looks cool lol
which clock do scientists use to measure time why
Scientists use Atomic clock to measure time
Electronic flash units for camera contain a capacitor for storing the energy used to produce the flash. In one such unit, the flash lasts for 1675s with an average light power output of 2.70 x 105 W . (a) If the conversion of electric energy to light is 95% efficient ( the rest of the energy goes to thermal energy), how much energy must be stored in the capacitor for one flash
Answer:
420J
Explanation:
Power is the time rate of change in energy. Power is the ratio of energy to time. The S.I unit of power is in watts.
Given that the flash lasts for 1/675 s, power output is 2.7 * 10⁵ W. Hence:
Power = Energy / time
Substituting:
2.7 * 10⁵ W = Energy / (1/675)
Energy = 2.7 * 10⁵ W * 1/675 = 400J
Therefore the energy emitted as light is 400J.
Since the conversion of electric energy to light is 95% efficient, hence the energy stored as electrical energy is:
Energy(capacitor) = 5% of 400J + 400J = 0.05*400 + 400
Energy(capacitor) = 420J
If a positively charged rod is brought near the knob of a positively charged electroscope, the leaves of the electroscope will...
A) converge, only
B) diverge, only
C) first diverge, then converge
D) first converge, then diverge
Answer:
B
Explanation:
if a positively charged rod is brought near the knob of a neutral electroscope, it will attract some electrons up from the leaves onto the knob. That process causes both of the leaves to be positively charged (excess protons), and the leaves will diverge.
I WILL MARK YOU THE BRAINLIEST NO LINKS
What type of friction is acting on the airplane?
sliding friction
static friction
fluid friction
rolling friction
Answer:
I believe it's sliding friction.
Explanation:
The energy principle states that:
Energy can be destroyed.
Energy can be created.
Energy cannot be created or destroyed.
Energy cannot be created, but it can be destroyed.
brainleist to correct answer
The energy principle states that:
[tex]\sf\purple{Energy \:cannot \:be \:created \:or\: destroyed.✅}[/tex]
Law of conservation of energy or the first law of thermodynamics states that energy can neither be created nor destroyed; it can only be transferred or changed from one form to another.[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{.}}}}}[/tex]
Electrical current is the flow of ____________
A) helium
B) protons
C) atoms
D) electrons
How much voltage is required to make 0.56 A flow through a 72-ohm resistance? [V = I x R]
A)48 V
B)36 V
C)40 V
D)52 V
WILL GIVE BRAINLIEST!!!
Solution :
A) Electric current is the flow of electrons .
B) We know, by ohm's law :
V = I × R
Putting given values in above equation, we get :
V = 0.56 × 72 V
V = 40.32 V
Hence, this is the required solution.
G.P.E = weight (n) x height (m). 2 identical twins are skiing down 2 different slopes. one is 1000m high, the other is 1500 m high. the twin at 1000m weighs 150 N. the other twin weighs 100 N. which twin has the most P.E before they begin skiing?
Answer:
I don't know i really I'm sorry I wish I could help
Suppose that Joe and Jim are twins and :
________________________________
Joe :
Height = 1000 m
==》 PE = 150 × 1000
Weight = 150 N
==》 PE = 150,000 j
_________________________________
Jim :
Height = 1500 m
==》PE = 100 × 1500
Weight = 100 N
==》PE = 150,000 j
______________________________
As u can see Joe and Jim has equal PE before they begin skiing .
?????? ?????help please
A rookie quarter back throws a football with an initial upward velocity component of 12.0 m/s and a horizontal velocity component of 20.0 m/s. Ignore resistance. How much time is required for the football to reach the highest point of the trajectory
Answer:
t = 1.22 s
Explanation:
Given that,
The initial upward velocity component of a football = 12 m/s
The horizontal velocity component is 20 m/s
We need to find the time required for the football to reach the highest point of the trajectory. Let the time is t.
Using first equation of motion to solve it such that,
[tex]v=u+at[/tex]
u is initial velocity
v is final velocity
a = -g
so,
[tex]t=\dfrac{u}{g}\\\\t=\dfrac{12}{9.8}\\\\t=1.22\ s[/tex]
So, the required time taken by the football to reach the highest point is 1.22 seconds.
Please hurry Describe why electric currents can be dangerous
Answer:
Cardiac Arrest, burns, and nerve damage.
Explanation:
Basically, the main risk is cardiac arrest, caused by the electric current interfering with the normal operation of the heart muscle. Other possible damages are burns due to the electric energy vaporizing the water inside the cells, and nerve damage caused by excessive current through the nerves.
The Keck Observatory is home to the largest Earth-based twin telescopes. The telescopes are located away from city lights, above the clouds where the atmosphere is clear, calm, and dry. In 1999, additional steps were taken to help the telescopes overcome any distortions caused by changes in the atmosphere by adding a laser sighting system. Now, the Keck telescopes can probe distant galaxies and capture images with more detail than even the Hubble Space Telescope. Scientists can now use the Keck telescopes to investigate many questions. What is one question the Keck telescopes would NOT help scientists answer
Answer:
Option D
Explanation:
The options for the question are
a) How do galaxies rotate?
b) What is the weather on Neptune?
c) What is the core of Saturn made of?
d) What other solar systems have planets?
Solution
The Hubble space telescope was designed and integrated into the extraterrestrial system in order to capture information about the surrounding universe. If the Keck Observatory has a better observation capacity than the Hubble space telescope then the scientist would be interested to know the surrounding planets in the solar system.
Hence, option D is correct
What is the period of a sound wave with a frequency of 20Hz?
As shown in the diagram below, a 1 kg rock tied to a rope is
swung by a boy. This rock has a constant speed of 5 m/s,
and the length of the rope is 1 m. The rock's angular
momentum is
Answer:
Explanation:
Angular momentum has a formula of L = mvr. Fillingin:
L = (1.0)(5.0)(1.0)
L = 5.0 kg*m/s
Which is a valid ionic compound?
sodide chlorine
sodium chlorine
sodium chloride
sodide chloride
Answer:
sodium chloride
Explanation:
Sodium chloride is an ionic compound. The ions of the sodium chloride compound is sodium ion and chloride ion. The sodium ion is cation while the chloride ion is an anion. Sodium chloride is a very stable compound because of the mutual attraction of oppositely charged ions.
Physicist ____ was found to have completely made up some of the data on which his astounding discoveries were made.
Answer:
Jan Hendrik Schön I believe
Which statement best describes the Sun Earth-Moon system?
Answer:
A
Explanation:
A. The Moon orbits the Earth, and the Earth-Moon system orbits the Sun
B. The Earth and Moon both orbit the Sun separately
C. The Sun orbits the Earth-Moon system
D. The Moon revolves around Earth but not the Sun
PLS HELP. URGENT.
I WILL MARK HIM/HER AS BRAINLIEST.
Answer:
Explanation:
frequency=1/time period
50=1/time
time=1/50
time=0.020 s
Answer: A
Explanation:
A spring with a spring constant of 2.5 N/m is stretched by 0.2 m. What is the potential energy in the spring
Answer:
Explanation:
PE = [tex]\frac{1}{2}k[/tex](Δ[tex]x^2[/tex])
where k is the spring constant and Δx is the displacement of the spring when an object is hung from it. Plugging in:
[tex]PE=\frac{1}{2}(2.5)(.2^2)[/tex] which gives us
PE = .05 J
difference between acceleration due to gravity and gravity
Answer:
The gravitational force between earth and any object is known as gravity.
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