Answer:
Density = 5 g/m³
Explanation:
Given:
Mass of block = 20 gm
Volume of block = 4 m³
Find:
Density
Computation:
Density = Mass / Volume
Density = 20 / 4
Density = 5 g/m³
5 kg/m3
Explanation:
The formula to find density is (d) = mass (m) ÷ volume (v)
i'd like you to explain this to me, I don't have a clue on how to do this
1. I would like you to then go into detail as to why this is an important discovery or application of this scientific principle.
2. Then I would like you to explain how this applies to what we have learned.
"discovery" - Spanish flu
scientific concept/principle - exponential growth
thank you!
Answer:
Explanation:
The Spanish flu pandemic of 1918, the deadliest in history, infected an estimated 500 million people worldwide about one-third of the planet’s population and killed an estimated 20 million to 50 million victims, including some 675,000 Americans. The 1918 flu was first observed in Europe, the United States and parts of Asia before swiftly spreading around the world. At the time, there were no effective drugs or vaccines to treat this killer flu strain. Citizens were ordered to wear masks, schools, theaters and businesses were shuttered and bodies piled up in makeshift morgues.
Does this sound familiar?
Its the same thing but with a different name called the Corona virus pandemic the same thing happened in 1918 and now it is happening again in 2020 , but in in 2020 there are far less people infected by the Corona virus as compared to the Spanish flu the numbers approximate around 70 million infected and deaths are around 2 million.
The rapid spread of Spanish flu in the fall of 1918 was at least partially to blame on public health officials unwilling to impose quarantines during wartime. The public health response to the crisis in the United States was further hampered by a severe nursing shortage as thousands of nurses had been deployed to military camps and the front lines. But one of the chief reasons that the Spanish flu claimed so many lives in 1918 was that science simply didn’t have the tools to develop a vaccine for the virus. Microscopes couldn’t even see something as incredibly small as a virus until the 1930s.
That is why the Spanish Flu claimed so many lives in 1918 and the Corona Virus didn't claim that many.
The Corona Virus patients with respect to Spanish Flu patients exponentially decreased because in 2020 we had the specific tools to fight the virus and since mankind was aware when the world engrossed into the pandemic 100 years before the new the risks that it could impose on the world , People started to Quarantine themselves, more nurses/doctors are available rather than in the era of the 19th century.
Mathematically we would say that the exponential growth would be:
[tex]y=ab^x[/tex]
This is an exponential function, which means as you increase x , y increases exponentially, and where a is the initial value and b is the growth factor.
For example:
There are 100,000 cases of Coronavirus when the virus outbroke. If the number of cases doubles every week then how many cases would be there in 10 weeks?
So the solution would be
[tex]y=ab^x\\y=100000(2)^{10}\\y=102400000[/tex]
Which means people infected with the virus would be approximate 102.5 million. But since this kind of pandemic already broke out in 1918 called the Spanish flu mankind was wise and controlled its growth factor (b) by Quarantining people , shutting down businesses, schools and implying them to work from home , closing off cafeteria's restaurants for dine in purposes and just allowing take away to reduce human contact, and since 1918 we have more doctors and nurses to treat the infected in 2020 we reduced the outbreak to 70 million in about 10 months other wise it could have been 100 million in just 2.5 months as we can see.
So guys stay indoors just go out if you REALLY need something, avoid meeting others , wear masks and gloves :)
This is an apparatus for studying the photoelectric effect. The work function of the material being investigated is 3.5 × 10–19 J. The battery is set at 1.5 V. What is the longest wavelength of light needed to produce an electric current from the cathode (C) to the anode (A)?
Answer:
The longest wavelength of light needed to produce current is 567.9 nm.
Explanation:
Given;
minimum energy required to produce electric current from the cathode to anode = work function, E = 3.5 x 10⁻¹⁹ J
E = hf
[tex]E = \frac{hc}{\lambda}[/tex]
where;
c is speed of light = 3 x 10⁸ m/s
λ is the longest wavelength of light needed to produce current
[tex]E = \frac{hc}{\lambda} \\\\\lambda = \frac{hc}{E} \\\\\lambda = \frac{(6.626\times 10^{-34})(3\times 10^8)}{3.5\times 10^{-19}}\\\\\lambda = 5.679 \times 10^{-7} \ m\\\\\lambda = 567.9 \times 10^{-9} \ m\\\\\lambda = 567.9 \ nm[/tex]
Therefore, the longest wavelength of light needed to produce current is 567.9 nm.
A body travels 10 meters during the first 5 seconds of its travel, and it travels a total of 30 meters over the first 10 seconds of its travel. What is
its average speed during the time from t 5 seconds to t - 10 seconds?
A. 2 meters/second
В. 3 meters/second
С. 4 meters/second
D. 5 meters/second
E. 6 meters/second
10 POINTS BE FAST
Which statement illustrates how progress in engineering has affected the
natural environment?(please hurry)
A. Modern mining practices provide materials that can be used for
technological advances.
B. Modern mining equipment has improved
the health and safety of
workers.
C. Extracting mineral resources
with modern mining equipment
removes fertile topsoil.
D. Mining companies use modern equipment to extract mineral
resources more efficiently.
hurry please
Answer:
I think it's c or A hopes this help
What is the minimum force require to move a 5kg wooden crate on a wooden floor?
14.7 m/s^2
20.6N
20.6 m/s^2
14.7N
You need to know the coefficient of static friction between a wooden object and a wooden surface. I'll denote it with µ. If you're given a specific value you should obviously use that.
By Newton's second law, the horizontal and vertical net forces are
• net horizontal:
∑ F = p - f = 0
• net vertical:
∑ F = n - w = 0
where
p = magnitude of the pushing force
f = mag. of friction
n = mag. of the normal force
w = weight of the crate
The second equation gives
n = w = (5 kg) (9.8 m/s²) = 49 N
Friction is proportional to the normal force by a factor of µ, so
f = µ (49 N) = 49µ N
To overcome static friction, the push has to exceed this in magnitude, so that
p > 49µ N
For instance, if p = 0.25, then p would need to greater than 12.25 N. (This example isn't particularly helpful, though, since both possibly correct options are larger than 12.25 N...)
A wheel starts from rest and rotates with constant angular acceleration to reach an angular speed of 11.9 rad/s in 3.10 s. (a) Find the magnitude of the angular acceleration of the wheel.
Answer:
The value is [tex]\alpha = 3.84 \ rad/s^2[/tex]
Explanation:
From the question we are told that
The constant angular speed is [tex]w = 11.9 \ rad/s[/tex]
The time taken is [tex]t = 3.10 \ s[/tex]
Generally the magnitude of the angular acceleration is mathematically represented as
[tex]\alpha = \frac{w}{t}[/tex]
=> [tex]\alpha = \frac{11.9}{ 3.10 }[/tex]
=> [tex]\alpha = 3.84 \ rad/s^2[/tex]
Two equal forces act at the same time on the same motionless object, but in opposite directions. Which statement best describes the object’s resulting motion? A. The object will accelerate. B. The object will change direction. C. The object will move at a constant speed. D. The object will remain motionless.
Answer:
D
Explanation:
The object will remain motionless(i just need points)
A force of 250 N is applied to a hydraulic jack piston that is 0.02 m in diameter. If the piston that supports the load has a diameter of 0.15 m, approximately how much mass can be lifted by the jack
Answer:
1400.38N
Explanation:
Step one
Given data
P1= 250N
D1= 0.02m
A1= πD1^2/4
substitute
[tex]A1= 3.142*0.02^2/4\\\\A1=3.142*10^-4[/tex]
D2= 0.15m
A1= πD2^2/4
[tex]A2= 3.142*0.15^2/4\\\\A2=1.76*10^-3[/tex]
Required
The load P2
Step two:
Applying the hydraulic expression for a non-compressible fluid
we know that
Pressure= force/are
P1/A1=P2/A2
[tex]250/3.142*10^-4= P2/1.76*10^-3[/tex]
cross multiply we have
P2= 1.76*10^-3*250/3.142*10^-4
P2=0.44/3.142*10^-4
P2=1400.38N
Which number is written using standard scientific notation?
O A. 40x10°
B. 10.29x10
C. 3.47x10-7
D. 0.02x102
help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 39 points and will give branlist asap!
Examine the diagram below and answer the following questions for 2 points each: Identify which graph shows an object that is not moving. Explain why. Identify which graph shows an object that is speeding up over time. Explain why. Identify which graph shows an object that is moving at a constant speed. Explain why. Question 15 options:
Answer:
Graph for object that is not moving: B
Graph for object that is speeding up: D
Explanation:
A.) In order to represent that an object is not moving, you must either show that there is no velocity (0 m/s) or show a position over time graph that is a horizontal line.
Because the position is the same as time increases, the graph shows that there the object must be at rest, as there is no change in position due to velocity. (Velocity must be 0m/s)
B.) In order to represent an object is speeding up, the position time graph must either be a positive exponential function, the velocity time graph must be a positive, linear line, or the acceleration over time graph must be a positive, horizontal line.
Why is D the correct answer? Because if an object is speeding up, you know that the value of its speed (velocity) is increasing at some rate. And since speeding up refers to positive change, the function of velocity over time graph must be a positive function.
A proton is projected toward a fixed nucleus of charge Ze with velocity vo. Initially the two particles are very far apart. When the proton is a distance R from the nucleus its velocity has decreased to 1/2vo. How far from the nucleus will the proton be when its velocity has dropped to 1/4vo
Answer:
The value is [tex]R_f = \frac{4}{5} R[/tex]
Explanation:
From the question we are told that
The initial velocity of the proton is [tex]v_o[/tex]
At a distance R from the nucleus the velocity is [tex]v_1 = \frac{1}{2} v_o[/tex]
The velocity considered is [tex]v_2 = \frac{1}{4} v_o[/tex]
Generally considering from initial position to a position of distance R from the nucleus
Generally from the law of energy conservation we have that
[tex]\Delta K = \Delta P[/tex]
Here [tex]\Delta K[/tex] is the change in kinetic energy from initial position to a position of distance R from the nucleus , this is mathematically represented as
[tex]\Delta K = K__{R}} - K_i[/tex]
=> [tex]\Delta K = \frac{1}{2} * m * v_1^2 - \frac{1}{2} * m * v_o^2[/tex]
=> [tex]\Delta K = \frac{1}{2} * m * (\frac{1}{2} * v_o )^2 - \frac{1}{2} * m * v_o^2[/tex]
=> [tex]\Delta K = \frac{1}{2} * m * \frac{1}{4} * v_o ^2 - \frac{1}{2} * m * v_o^2[/tex]
And [tex]\Delta P[/tex] is the change in electric potential energy from initial position to a position of distance R from the nucleus , this is mathematically represented as
[tex]\Delta P = P_f - P_i[/tex]
Here [tex]P_i[/tex] is zero because the electric potential energy at the initial stage is zero so
[tex]\Delta P = k * \frac{q_1 * q_2 }{R} - 0[/tex]
So
[tex]\frac{1}{2} * m * \frac{1}{4} * v_o ^2 - \frac{1}{2} * m * v_o^2 = k * \frac{q_1 * q_2 }{R} - 0[/tex]
=> [tex]\frac{1}{2} * m *v_0^2 [ \frac{1}{4} -1 ] = k * \frac{q_1 * q_2 }{R}[/tex]
=> [tex]- \frac{3}{8} * m *v_0^2 = k * \frac{q_1 * q_2 }{R} ---(1 )[/tex]
Generally considering from initial position to a position of distance [tex]R_f[/tex] from the nucleus
Here [tex]R_f[/tex] represented the distance of the proton from the nucleus where the velocity is [tex]\frac{1}{4} v_o[/tex]
Generally from the law of energy conservation we have that
[tex]\Delta K_f = \Delta P_f[/tex]
Here [tex]\Delta K[/tex] is the change in kinetic energy from initial position to a position of distance R from the nucleus , this is mathematically represented as
[tex]\Delta K_f = K_f - K_i[/tex]
=> [tex]\Delta K_f = \frac{1}{2} * m * v_2^2 - \frac{1}{2} * m * v_o^2[/tex]
=> [tex]\Delta K_f = \frac{1}{2} * m * (\frac{1}{4} * v_o )^2 - \frac{1}{2} * m * v_o^2[/tex]
=> [tex]\Delta K_f = \frac{1}{2} * m * \frac{1}{16} * v_o ^2 - \frac{1}{2} * m * v_o^2[/tex]
And [tex]\Delta P[/tex] is the change in electric potential energy from initial position to a position of distance [tex]R_f[/tex] from the nucleus , this is mathematically represented as
[tex]\Delta P_f = P_f - P_i[/tex]
Here [tex]P_i[/tex] is zero because the electric potential energy at the initial stage is zero so
[tex]\Delta P_f = k * \frac{q_1 * q_2 }{R_f } - 0[/tex]
So
[tex]\frac{1}{2} * m * \frac{1}{8} * v_o ^2 - \frac{1}{2} * m * v_o^2 = k * \frac{q_1 * q_2 }{R_f }[/tex]
=> [tex]\frac{1}{2} * m *v_o^2 [-\frac{15}{16} ] = k * \frac{q_1 * q_2 }{R_f }[/tex]
=> [tex]- \frac{15}{32} * m *v_o^2 = k * \frac{q_1 * q_2 }{R_f } ---(2)[/tex]
Divide equation 2 by equation 1
[tex]\frac{- \frac{15}{32} * m *v_o^2 }{- \frac{3}{8} * m *v_0^2 } } = \frac{k * \frac{q_1 * q_2 }{R_f } }{k * \frac{q_1 * q_2 }{R } }}[/tex]
=> [tex]-\frac{15}{32 } * -\frac{8}{3} = \frac{R}{R_f}[/tex]
=> [tex]\frac{5}{4} = \frac{R}{R_f}[/tex]
=> [tex]R_f = \frac{4}{5} R[/tex]
a 12-kg block is pulled by a string at a 30 degree angle. if the string exerts a 50 n force, the block accelerates at 4.13 m/s2. what is the frictional force and normal force exerted on the block?
Let, frictional force is f and normal force is N.
Balancing horizontal forces :
[tex]50cos \ 30^o - f = 12 \times 4.13\\\\f = 50cos \ 30^o - 49.56\\\\f = -6.26\ N[/tex]
Also, balancing vertical forces, we get :
[tex]N = mg + 50sin \ 30^o\\\\N =( 12\times 9.8 ) + (50\times sin \ 30^o)\\\\N = 142.6\ N[/tex]
Therefore, the frictional force and normal force is -6.26 N and 142.6 N.
HELP WILL GIVE BRAINLIEST OF CORRECT
Answer:
B)
Explanation:
The answer is B)- The object's speed must be changing.
So will I get the Brainliest...
When using an open flame or hot plate,
which of the following should be used
as a safety precaution to avoid burns?
A. test tube
B. beaker
C. hot pad or mit
D. safety goggles
A rugby players runs 10.0 m straight down the playing field in 2.00 s. The player is then hit and pushed 5.00 m straight backward in 1.50 s. The player breaks the tackle and runs straight forward another 17.2 m in 4.10 s. Calculate the velocity for the players entire motion.
Answer:
2.92 m/s
Explanation:
For the entire motion, the average velocity (V) can be calculated thus;
V = [tex]\frac{displacement}{time}[/tex]
Total displacement of the player = 10.0 + (-5) + 17.2
= 22.2 m
Total time = 2.00 + 1.50 + 4.10
= 7.60 s
V = 22.2/7.60
= 2.92 m/s
Hence, the velocity of the players for the entire motion is 2.92 m/s.
Determine the wavelength of a wave with a frequency of 100hz and a velocity of 5m/s.
We are given:
Frequency of the wave = 100 Hz
Velocity of the wave = 5 m/s
Finding the Wavelength:
We know the relation between the wavelength and frequency is:
u = νλ [where ν is the frequency, u is the speed and λ is the wavelength]
5 = 100*(λ)
λ = 5/100 [dividing both sides by 100]
λ = 1/20
λ = 0.05 m
Hence, the wavelength is 0.05 m
Two forces with magnitudes of 6 pounds and 18 pounds are applied to an object. The magnitude of the resultant is 13 pounds. Find the measurement of the angle between the resultant vector and the vector of the 18 pound force to the nearest whole degree.
Answer: the angle between the resultant vector and the vector of the 18 pound is 28°
Explanation:
given that data in the question; as its interpreted in the diagram below;
from the cosine rule, we know that;
a² = b² + c² - 2bc
so
(13)² = (6)² + (18)² - (2 × 6 × 18 ) cos∅
169 = 36 + 324 - 216cos∅
169 = 360 - 216cos∅
216cos∅ = 360 - 169
216cos∅ = 191
cos∅ = 0.8842
∅ = cos⁻¹ ( 0.8842 )
∅ = 27.8° ≈ 28° {nearest whole number}
Therefore the angle between the resultant vector and the vector of the 18 pound is 28°
if a person does not just do what you told what happens
Answer:
Of course we feel bad or angry.
Explanation:
that it what i know....
Consider a box with the same mass and velocity instead sliding without friction toward the incline. How does this object's kinetic energy before the incline compare to the sphere
Answer:
Object's kinetic energy is high on frictionless medium.
Explanation:
There is a great difference in object's kinetic energy which is present between sliding with friction and sliding without friction because friction decreases the speed of an object so if an object moves on the frictionless medium, it moves and covers more distance and we can say that the object has more kinetic energy while on the other hand, if a body moves on the medium and experience friction so it moves with little speed so we can say that the body has low kinetic energy.
Which of the following statements about elements and atoms is true?
A. Atoms are the smallest unit of an element.
B. Atoms are made of particles called elements.
C. Elements are made of more than one type of atom.
D. Elements are changed into atoms by a chemical reaction.
hmu^^^^
Answer:
A. Atoms are the smallest unit of an element.
Explanation:
The correct statement from the given choices is that atoms are the smallest unit of an element.
Atoms are the smallest particles that takes part in chemical reactions and they are made up of protons, neutrons and electrons.
Elements are distinct substances that cannot be split up into simpler substances. They are made up of only one kind of atoms. Elements are not changed into atoms by chemical reactions. In chemical reactions, atoms simply recombine.PLease help i will give brainliest
Answer:
1. False
2. Fats
3. False
Explanation:
MyPlate is an initiative from the United States Department of Agriculture that is designed to help Americans improve their eating habits throughout their lifetimes. Every meal matters. The five food groups represented in My Plate include vegetables, grain, dairy, protein foods, and fruits.
Calories are a source of energy for the human body. So, the more active a person is, the more energy he would need to be supplied to him in form of calories. The less active a person is, the fewer calories he would need.
suppose a wireless charging system of an electric toothbrush. the charger has solenoid 1 with 800 turns and the toothbrush has solenoid 2 with 150 turns what is the mutual inductance
Complete Question
Suppose a wireless charging system of an electric toothbrush. The charger has Solenoid 1 with 800 turns and the toothbrush has Solenoid 2 with 150 turns. The current in the charger is 220 mA and the corresponding average magnetic flux through Solenoid 2 is 0.056 Wb. What is the mutual inductance of the pair of the solenoids?
Answer:
The value is [tex]M = 38.2 \ H[/tex]
Explanation:
From the question we are told that
The number of turns of solenoid 1 is [tex]N_1 = 800[/tex]
The number of turns for solenoid 2 is [tex]N_2 = 150 \ turns[/tex]
The current in the charger is [tex]I = 220 \ mA = 220 *10^{-3} \ A[/tex]
The magnetic flux through solenoid 2 is [tex]\phi = 0.056 \ Wb[/tex]
Generally mutual inductance is mathematically represented as
[tex]M = \frac{N_2 * \phi }{ I }[/tex]
=> [tex]M = \frac{150 * 0.056 }{ 220 *10^{-3} }[/tex]
=> [tex]M = 38.2 \ H[/tex]
A 0.3 g mosquito is flying toward a girl with a speed of 4.5 mph. Just before landing on the girl, the fly is swatted straight back at a speed of 12 mph. If the fly swatter and the fly were in contact for 0.2 s, what is the force that was exerted on the fly
Answer:
1.1x10^-2N
Explanation:
We have the change in momentum as
P = 0.3(4.5+12)g.mph
= 0.3x0.447x(4.5+12)x10^-3
Then the force that is exerted will be
F = p/∆t
∆t = 0.2
= 0.3x0.447x(4.5+12)x10^-3/0.2
= 0.1341x16.5x10^-3/0.2
= 1.1x10^-2
Therefore the force that was exerted is equal to 1.1x10^-2
The required magnitude of the force exerted on the fly is of [tex]5.025 \times 10^{-3} \;\rm N[/tex].
Given data:
The mass of mosquito is, [tex]m =0.3 \;\rm g =3 \times 10^{-4} \;\rm kg[/tex]
The speed of flying is, u = 4.5 mph = 4.5 ( 0.447) = 2.01 m/s.
The swatting speed of mosquito is, v = 12 mph = 12 (0.447 ) = 5.36 m/s.
The time of contact is, t = 0.2 s.
In this problem, we will first calculate the change in momentum, and the change in momentum is given as,
p = m ( v - u)
Solving as,
[tex]p = 3 \times 10^{-4} (5.36 - 2.01)\\\\p = 1.005 \times 10^{-3} \;\rm kg.m/s[/tex]
Now as per the Newton's second law,
[tex]F = p/t\\\\F = 1.005 \times 10^{-3} / 0.2\\\\F= 5.025 \times 10^{-3} \;\rm N[/tex]
Thus, the required magnitude of the force exerted on the fly is of [tex]5.025 \times 10^{-3} \;\rm N[/tex].
Learn more about the Newton's second law here:
https://brainly.com/question/19860811
Question 2: Start-Up
Now you will use another Tracker experiment to examine the displacement, velocity, and acceleration of a car in the x (horizontal) direction. To
begin your investigation, open the Tracker Car Start-up experiment.
Part A
Play () the video. At the end, rewind (H) and step forward (►) one frame ata time to observe the step-by-step changes in position. Based on
your observations, describe the car's displacement (distance and direction from the starting place) over time.
Answer:
The car starts moving in the positive direction at x = 0.2 seconds. Initially it moves very little, but it covers a greater distance with each time increment.
Explanation:
Answer: The car starts moving in the positive direction at x = 0.2 seconds. Initially it moves very little, but it covers a greater distance with each time increment.
Explanation: edmentum sample answer
how much work is needed to move an object 20 meters with 40 newtons of force?
Answer: c I think is the answer
Explanation:
9. A 15kg mass is lifted upward at a constant speed to a height of 22 m. Calculate the work done by the lifting
force.
Work done by lifting is 3,300 Newton.
Given that;
Mass of thing = 15 kg
Height lifted = 22 m
Find:
Work done by lifting
Computation:
Work done = mgh
Work done by lifting = (15)(10)(22)
Work done by lifting = 3,300 Newton
Learn more:
https://brainly.com/question/14729868?referrer=searchResults
it is difficult to walk on a smooth floor why
Answer:
because theres is not enough friction so it will be super slippery
Explanation:
A runaway train car that has a mass of 15,000 kg travels at a speed of 5.4 m/s down a track. Compute the time required for a force of 1500 N to bring the car to rest.
The 1500 N force would need to act in the direction opposite the train car's movement, so if we take the current direction it's moving in to be positive, we have by Newton's second law
-1500 N = (15,000 kg) a → a = -0.10 m/s²
If t is the time it takes for the train to come to rest, then
-0.10 m/s² = (0 - 5.4 m/s) / t
t = (5.4 m/s) / (0.10 m/s²) → t = 54 s
calculate the number of molecules of hydrogen and carbon present in 4 g of methane
Answer:
Answer = 6.022×10²³ molecules of CH4 which consists of 1 mole of C atoms and 4 moles of H atoms.
A teammate starts taking an all-natural supplement to improve strength and body shape and recommends you take it, too. This is an example of
Answer:
Explanation:
online personal fittness