a box of mass 4kg slides on the horizontal surface with kinetic frictional force of 8N. what coefficient of friction between the box and horizontal surface
Answer:
ų=0.8
Explanation:
F=mg
F=4×9.81=39.24N
Ff=Fn-F
=39.24-8=31.24
ų=Ff÷Fn
=31.24÷39.24
=0.8
A group of students designed the string drip system to water plants without irrigation, as shown in the image. They placed a jug
next to a plant with the jug's mouth above the plant's pot. Then, they placed one end of a piece of cotton string at the bottom of
the jug and inserted the other end into the soil, about 8 cm deep, close to the plant's root. They kept the string out of direct
sunlight. Finally, they added water to the jug. After a few days, the students decided that their drip was too slow.
ago
How might the students modify their design to increase the controlled drip?
O A.
use a wider jug
B. use a longer string
O c. add more water to the jug
O D. add more strings to the design
Answer:
D add more string and water
Why does the needle of a compass point north?
a. Because the southern pole of the Earth's magnet repels it.
b. Because the southern pole of the Earth's magnet is in the north.
Because the northern pole of the Earth's magnet is in the north
d. Because the Earth's core is made of steel.
C.
Answer:
b. Because the southern pole of the Earth's magnet is in the north.
Explanation:
This is very weird to think about but Earth's southern magnetic pole is in Earth's geographic north. So when compass points north, it is actually getting attracted to the southern magnetic pole (that is actually located in the north direction- geographic location- in earth).
Why x rays have different properties from light even though both originate from orbital transition of electrons in excited atoms?
Answer:
he difference between X-rays and visible radiation is in the energy of each foton.
Explanation:
Visible light and X-rays are electromagnetism waves with the same origin betray the atomic, but the energy of transioin wings is different,
E = h (v_f - v₀)
With this equation we see that the energy is proportional to the difference between the atomic levels where the ranscion occurs, the X-rays the transition involves deep levels n = 1 or 2 for which the energy of the emitted photon is very high.
The visible radiation the transition is between levels closer so that the emitted light has a lower frequency and is in the range of the visibly
Consequently, the difference between X-rays and visible radiation is in the energy of each foton.
The length of a planet's day is determined by it's
Answer: "People will say the length of a day is determined by just the rotation rate of a planet, but that isn’t entirely true. The orbit around its sun also factors in. What we define as a day is the time between when the Sun is highest in the sky until the next time the Sun is at the highest point in the sky. This isn’t just the time it takes the Earth to rotate once on its axis, though. This is because, as the Earth is rotating, it’s also moving relative to the Sun"
A (200 g) of water at (80 °C) is mixed with (100 g)of water at (20 °C). What is the final temperature of the water?
Answer:
60 °C
Explanation:
From the question given above, the following data were obtained:
Mass of 1st sample (M₁) = 200 g
Temperature of 1st sample (T₁) = 80 °C
Mass of 2nd sample (M₂) = 100 g
Temperature of 2nd sample (T₂) = 20 °C
Equilibrium temperature (Tₑ) =?
NOTE: Since the sample are the same, the specific heat capacity is constant.
We can obtain the equilibrium temperature as follow:
Heat lost by 1st = heat gained by the 2nd
M₁C(T₁ – Tₑ) = M₂C(Tₑ – T₂)
Cancel out C
M₁(T₁ – Tₑ) = M₂(Tₑ – T₂)
200 (80 – Tₑ) = 100 (Tₑ – 20)
Clear bracket
16000 – 200Tₑ = 100Tₑ – 2000
Collect like terms
16000 + 2000 = 100Tₑ + 200Tₑ
18000 = 300Tₑ
Divide both side by 300
Tₑ = 18000 / 300
Tₑ = 60 °C
Therefore, the equilibrium temperature (i.e the final temperature) of the mixture is 60 °C.
em 6
Which provides a definition for
matter?
Anything that
A.
B.
C.
D.
is solid and has weight
takes up space and is heavy
takes up space and has mass
is a liquid or solid
Answer:
definition of matter is that matter takes up space and has mass
which answer is it??
Answer:
hmm...
Explanation:
Answer: wave a has the higher ampllitude while wave b has the lower amplitude.
Explanation:
wave a has the amplitude of 4 while wave b has the amplitude of one
Usami Bolt has a mass of 85kg and is running at a steady speed of 10m/s how much kinetic energy does he have
Answer:
Ek = 4250 J
Explanation:
Data:
m = 85 kgv = 10 m/sEk = ?Formula:
[tex]\boxed{\bold{Ek=\frac{m*(v)^{2}}{2}}}[/tex]Replace and solve:
[tex]\boxed{\bold{Ek=\frac{85\ kg*(10\frac{m}{s})^{2}}{2}}}[/tex][tex]\boxed{\bold{Ek=\frac{85\ kg*100\frac{m^{2}}{s^{2}}}{2}}}[/tex][tex]\boxed{\bold{Ek=\frac{8500\ J}{2}}}[/tex][tex]\boxed{\boxed{\bold{Ek=4250\ J}}}[/tex]It has 4250 Joules of Kinetic Energy.
Greetings.
Calculate the gravitational force of attraction betweentwo 55 kg people who are standing 0.25 m apart.
Answer:
F=GMm/r²
G=6.67x10^-11
F= 6.67x10^-11 x 55 x 55/(0.25)²
=3.228 x 10^-6N
The gravitational force of attraction between the two people is 3.23 × 10⁻⁶ N
From Newton's law of universal gravitation formula, we have that
[tex]F = G\frac{m_{1}m_{2} }{r^{2} }[/tex]
Where F is the gravitational force
G is the gravitational constant (G = 6.67408 × 10⁻¹¹ m³.kg⁻¹.s⁻²)
m₁ is the mass of object 1
m₂ is the mass of object 2
and r is the distance between the centers of the masses
From the question
m₁ = 55 kg
m₂ = 55 kg
r = 0.25 m
Putting the parameters into the formula, we get
[tex]F = 6.67408 \times 10^{-11} \times \frac{55 \times 55}{0.25^{2} }[/tex]
∴ F = 3.23 × 10⁻⁶ N
Hence, the gravitational force of attraction between the two people is 3.23 × 10⁻⁶ N
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Determine the applied force required to accelerate a 2.25 kg object rightward with a
constant acceleration of 1.50 m/s2 if the force of friction opposing the motion is 18.2 N.
(Neglect air resistance.)
Answer:
Explanation:
Im going to be using the rules for significant digits properly so I hope you're quite familiar with them. The equation we need for this is
F - f = ma where F is the applied force (our unknown), f is the frictional force, m is the mass, and a is the acceleration. Filling in:
F - 18.2 = 2.25(1.50) and
F = 2.25(1.50) + 18.2 Do the multiplication first and round to get
F = 3.38 + 18.2 The addition rules tell us that we will be rounding to the tenths place after we add to get
F = 21.6 N
HI PLEASE HELP!
How do glow sticks affect the temperature of hot an cold water?
Will give brainliest. Will report any links or irrelevant answers so don’t even try.
Answer:
Chemical reactions occur slower at lower temperatures and faster at higher temperatures. When you put a glow stick in cold water, the chemical reaction slows down but will last for a longer period of time. When you put a glow stick in hot water, the reaction speeds up but will be over quicker.
Explanation:
(self-explanatory)
I hope this helps, have a nice day.
which is the term for the study of weather and climate?
Answer:
Meteorology
Explanation:
That is indeed the study of weather and climate.
plz help plz i cant do it
A : KE = 0 j & PE = 4 j
B : KE = 2 j & PE = 2 j
C : KE = 4 j & PE = 0 j
D : KE = 0 j & PE = 4 j
Answer:
Hey buddy this is the correct answer
Explanation:
A : KE = 0 j & PE = 4 j
B : KE = 2 j & PE = 2 j
C : KE = 4 j & PE = 0 j
D : KE = 0 j & PE = 4 j
HAVE A GREAT DAY<3
A parallel combination of 3ohms and 4ohms resistor is connected in series with a resistor of 4ohms and a battery of negligible resistance. Calculate the effective resistance in the circuit
Answer:
Explanation:
Equivalent resistance of parallel combination of two resistors of 3 ohms and 4 ohms .
R₁ = 3 x 4 / ( 3 + 4 )
= 12 / 7 = 1.7 ohms .
This equivalent resistance is connected with 4 ohms in series
Total resistance = 1.7 ohms + 4 ohms
= 5.7 ohms.
Hence effective resistance of the circuit = 5.7 ohms .
If an object is in freefall it will experience air blank which generates a drag force
Answer:
Resistance
Explanation:
I believe it is air resistance but I could be wrong.
The question is fishing for "air resistance", but that's a mistake by whoever wrote the question.
"Free fall" means that gravity is the ONLY force on the body. If there's any air resistance, then it's not free fall.
What does 'MET' stands for?
Answer:
MET = Metabolic equivalent of task.The point A on the above graph is an example of
extrapolation
variation
interpolation
average method
Answer:
Interpolation
Explanation:
The graph shows that it falls between 2 values and interpolation means that you estimate the unknown values that fall between the 2 values. Hope this helps!
The data point A is between two given data points and it lies within the line connecting the data points, thus we can conclude that point A is an example of interpolation.
Extrapolation is the process of extending a line connecting the data points beyond the given data points to make inferences based on the previous trend of the data set. This helps us to understand what will happen in the future if the trend continues in the same manner.
Interpolation is the process of determining an unknown variable between two known variables. In this process the data point is located within the line connecting the data points.
In this given graph, the data point A is between two given data points and it lies within the line connecting the data points, thus we can conclude that point A is an example of interpolation.
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which clock do scientists use to measure time why
Scientists use Atomic clock to measure time
The sunlight reaches the ground through radiation
Answer:
y e s
Explanation:
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.
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pls answer my quetion i will give brainlist answer
Answer:
here's an explanation but not the answer
please kindly send No or Yes understand.
Explanation:
A 10-N force is applied to push a block across a friction free surface for a displacement of 5.0 m to the right.
See Answer
See Answer
A 10-N frictional force slows a moving block to a stop after a displacement of 5.0 m to the right.
In a physics lab, Ray Zuvlite arranges two mirrors with a right angle orientation as shown. Ray then directs a laser line at one of the mirrors. The light reflects off both mirrors as shown. If angle A is 25°, determine the what is the angle measure of angles B, C, and D?
Answer:
B = 25°
C = 65°
D = 25°
Explanation:
The given parameters are;
The orientation of the two mirrors = At right angle to each other
The laser light is directed at one of the mirror
The measure of angle, A = 25°
The measures of angle B, C, and D are found as follows;
We have;
∠A = ∠B = 25°, by angle of incidence equals angle of reflection
∠B = 25°
∠B + ∠C = 90° by sum of the acute angles of a right triangle
25° + ∠C = 90°
∴ ∠C = 90° - 25° = 65°
∠C = 65°
∠E = ∠C = 65° by angle of incidence equals angle of reflection
∴ ∠E = 65°
Line 'L' is perpendicular to the second mirror, therefore, the angle between line 'L' and the second mirror = 90° = ∠E + ∠D
∠E + ∠D = 90°, by angle sum property
Therefore;
65° + ∠D = 90°
∴ ∠D = 90° - 65° = 25°
∠D = 25°
In general, ionic bonds form between a metal and a nonmetal. Covalent bonds usually form between two nonmetals. Which of the following pairs of atoms is most likely to form a covalent bond?
A. magnesium and chlorine
B. copper and bromine
C. nitrogen and oxygen
D. potassium and phosphorus
Answer:
C
Explanation:
Nitrogen and Oxygen donates electron to each other
Nitrogen and oxygen has the greatest chance of forming a covalent bond. Option C is correct.
What is a covalent bond?Covalent bonds are chemical bonds that keep atoms of different elements together while sharing electrons.
Compounds can be polar covalent or nonpolar covalent, depending on the electronegativity variations between components.
The nitrogen family, Group 15, can react with oxygen in a variety of ways. Nonmetallic elements include nitrogen and phosphorus and oxygen.
Ionic bonds often occur between a metal and a nonmetal. Covalent bonds are most commonly formed between two nonmetals.
Nitrogen and oxygen has the greatest chance of forming a covalent bond from given a pair of atoms.
Hence,option C is correct.a given
To learn more about the covalent bond, refer to the link;
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The space shuttle travels at 15,000 m/s in order to enter
earth atmosphere it changes it's speed to 10,000 m/s over
100 seconds. What is the space shuttles acceleration?
Answer:
10,000 m/s per 100 seconds
Emma compares the time it takes for a large marble and a small marble to roll down a slope. To make the findings reliable, Emma should..
Answer:
use two marbles that are having the same mass.
Explanation:
An experiment can be defined as an investigation which typically involves the process of manipulating an independent variable (the cause) in order to be able to determine or measure the dependent variable (the effect).
This ultimately implies that, an experiment can be used by scientists to show or demonstrate how a condition causes or gives rise to another i.e cause and effect, influence, behavior, etc in a sample.
Compare and contrast is used for the comparison of two or more things to show similarities and differences i.e how they are alike and different.
In this scenario, Emma compares the time it takes for a large marble and a small marble to roll down a slope.
In order to make his findings reliable, Emma should use two marbles that are having the same mass i.e two large marbles with the same mass and two small marbles with the same mass.
Mass can be defined as a measure of the amount of matter an object or a body comprises of. The standard unit of measurement of the mass of an object or a body is kilograms. Irrespective of the location of an object or a body at a given moment in time, the mass (amount of matter that they're made up of) is constant.
HELP⚠️⚠️
Your Best friend gets on a ship and travels away fast. They return 10.0 years later and I’ve only aged 4.00 years. How fast was your friend traveling? Give your answer as ex. 0.5c
Answer:
I think u are traeling at speed of light and not ur friend
Explanation:
If g were 15 instead of 9.81, what would your quads look like?
Answer:
Quads will have more energy
Explanation:
If the acceleration due to gravity increases from 9.81 to 15, then the velocity will increase as the rate of changing velocity i.e acceleration has increased from 9.81 to 15 m/s^2
With increase of velocity, the energy and force will also increase. Hence, the squad will require/have higher energy.
A helium nucleus is composed of two protons (positively charged) and two neutrons (charge neutral). The distance between the two protons in the nucleus is 5.18E-15 m. What is the electric force between the two protons (in Newtons; use positive sign for repulsive forces and negative sign for attractive forces)
Answer:
Using the given values
F = K q^2 / r^2 = 9 * 10E9 * (1.6 * E-19)^2 / (5.18 * E-15)^2 N
E = 9 * 1.6^2 / 5.18^2 * 10 = 8.5 N
The force between two protons will be 9 N (approx.)
We have two Protons (positively charged) and two Neutrons (charge neutral) inside a Helium atom. The distance between the two Protons in the nucleus is 5.18 x [tex]10^{-15}[/tex] m.
We have to determine the the electric force between the two protons.
State Coulomb's Law of Electrostatic force.The Coulomb's law states that the magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them. Mathematically -
[tex]$F=\frac{q _{1}\c q _{2}}{4 \pi \varepsilon _{0} r^{2}}[/tex]
According to question, we have -
Number of protons = 2
Distance between them (r) = 5.18 x [tex]10^{-15}[/tex] m.
We know charge on proton (q[1] = q[2]) = 1.6 x [tex]10^{-19}[/tex] C.
Substituting the values in the equation, we get -
[tex]$F = 9\times 10^{9}\; \times \frac{(1.6\times 10^{-19}) ^{2} }{(5.18\times 10^{-15}) ^{2} }[/tex]
Solving, we get -
F = 9 N (approx.)
Hence, the force between two protons will be 9 N (approx.)
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difference between acceleration due to gravity and gravity
Answer:
The gravitational force between earth and any object is known as gravity.
...