Explanation:
Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil. But almost all crucial tasks cannot be carried out without the presence of friction. ... Hence it is considered as a necessary evil .
Explanation:
Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil. But almost all crucial tasks cannot be carried out without the presence of friction. ... Hence it is considered as a necessary evil .
Excluding the noble gas group, how does the number of valence electrons in an element influence its chemical stability?
A. Elements with intermediate numbers of valence electrons are the last chemically stable.
B. Elements with the highest number of valence electrons are the most chemically stable.
C. Elements with intermediate number of valence electrons are the most chemically stable.
D. Elements wit the lowest number of valence electrons are the most chemically stable.
Answer:
C. Elements with intermediate number of valence electrons are the most chemically stable.
A 8.57-m ladder with a mass of 21.4 kg lies flat on the ground. A painter grabs the top end of the ladder and pulls straight upward with a force of 258 N. At the instant the top of the ladder leaves the ground, the ladder experiences an angular acceleration of 1.63 rad/s2 about an axis passing through the bottom end of the ladder. The ladder's center of gravity lies halfway between the top and bottom ends. (a) What is the net torque acting on the ladder
Answer:
[tex]1311.5\ \text{Nm}[/tex]
Explanation:
l = Length of ladder = 8.57 m
m = Mass of ladder = 21.4 kg
F = Force on ladder = 258 N
[tex]\alpha[/tex] = Angular acceleration = [tex]1.63\ \text{rad/s}^2[/tex]
g = Acceleration due to gravity = [tex]9.81\ \text{m/s}^2[/tex]
Net torque is given by
[tex]\tau=lf-\dfrac{l}{2}mg\\\Rightarrow \tau=8.57\times 258-\dfrac{8.57}{2}\times 21.4\times 9.81\\\Rightarrow \tau=1311.5\ \text{Nm}[/tex]
The net torque acting on the ladder is [tex]1311.5\ \text{Nm}[/tex].
Explain in detail why you cannot hear in space but you can see light(explanation includes particle movement of liquid, solids, gases, and plasma)
Answer:
The reason why one cannot hear in space but light can be seen is because light and sound are different kinds of wave
Light is an electromagnetic wave that propagates by a changing magnetic field hat creates a changing electric field. Light is created by a vibrating electric charge, and is transmitted through a medium by the absorption and reemission of the light by the medium particles
Sound is a longitudinal mechanical wave that is propagated by the vibration of the particles of the medium.
Sound requires a medium to propagate and it cannot be propagated or heard through space which is a vacuum.
Sound is created by a source that is vibrating and the vibration is transmitted to particles in the medium including solids, liquids, gases and plasma that the vibrating energy is in direct contact with and the transfer of the sound energy continues between layers of adjacent particles for the medium for the sound to be propagated from place to place
Explanation:
If you walk for 1.5 hours at an average speed of 4 miles/hr. How far will you have walked?
When electrons are shared unequally a/an
bond is formed
A dentist uses a small concave mirror to locate a cavity in a patient's tooth. The focal length of the mirror is 2.00 cm. If the mirror is held 1.60 cm from the tooth, how many times bigger will the image be? (In other words, what is the magnification?)
Answer:
m = 4.0
Explanation:
For this exercise in geometric optics we will use the equation of the constructor
[tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}[/tex]
where f is the focal length, p and q are the distance to the object and image, respectively.
In the exercise indicate the focal length f = 2.00 cm, the distance to the object p = 1.60 cm, let's find the distance to the image
[tex]\frac{1}{q} = \frac{1}{f} - \frac{1}{p}[/tex]
let's calculate
[tex]\frac{1}{q} = \frac{1}{2} - \frac{1}{1.6}[/tex]1 / q = ½ - 1 / 1.6
[tex]\frac{1}{q}[/tex] = -0.125
q = -8 cm
the magnification is
m = - q / p
m = 8/2
m = 4.0
Calculate the first and second velocities of the car with three washers attached to the pulley, using the formulas
v1 = 0.25 m / t1, and
v2 = 0.25 m / (t2 – t1)
where t1 and t2 are the average times the car took to reach the 0.25 and the 0.50 meter marks. Record these velocities, to two decimal places, in Table E.
What is the first velocity of the car with three washers at the 0.25 meter mark?
m/s
What is the second velocity of the car with three washers at the 0.50 meter mark?
m/s
Answer:
0.19 and 0.45
Explanation:
edge
The first and second velocities of the car are [tex]0.25/t_1[/tex] and [tex]0.50/t_2[/tex]respectively.
What is velocity?The velocity of an object is defined as the product of the distance travelled in a given direction and the time required to travel that distance. The velocity is expressed mathematically as,
v = d/t
Here, d represents the travelled distance.
And t is the typical amount of time needed to go the distance.
Given,
The value of the first distance is, d1 = 0.25 m.
The value of the second distance is, d2 = 0.50 m.
Then the first velocity of the car at 0.25 m is,
[tex]v_1 = d_1/t_1\\v_1 = 0.25 / t_1[/tex]
Thus,[tex]t_1[/tex] denotes the first distance's typical time.
The second velocity of the car with three washers at the 0. 50 m mark is
[tex]v_2 = d_2/t_2\\v_2 = 0.50 /t_2[/tex]
Here, [tex]t_2[/tex] stands for the second distance's typical time.
Thus, the first and second velocities of the car are [tex]0.25/t_1[/tex] and [tex]0.50/t_2[/tex]respectively.
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How do you get DC current and AC current? from a generator?
Answer:
They do that by converting rotating mechanical energy into electrical power. Portable generators use an engine—typically running on gasoline, diesel, or propane, to turn an alternator which produces alternating electrical current or AC.
Two train cars with the same mass (30,000 kg) are traveling in the same direction when they collide.
Train Car A has a velocity of 10 m/s and Train Car B has a velocity of 5 m/s. What is their total
momentum after the collision? Make sure to show all your work and include proper units.
Answer:
25
Explanation:
I just did this
A race car has a mass of 710kg. It starts from rest and speeds up to 12m/s in 12.0s. The car is uniformly accelerated during the entire time. What net force is applied to it?
A satellite orbits earth at constant speed in circular orbit.Which statement is correct? A The resultant force on the satellite is zero. B The resultant force on the satellite is towards the Earth. C The resultant force on the satellite is away from the Earth. D The resultant force on the satellite is in the direction of motion.
Answer:
B The resultant force on the satellite is towards the Earth.
Explanation:
In the case when the satellite orbits earth would be at constant speed in the circular orbit so hee the resultant force that on the satellite would be with regard to the earth
So as per the given situation, the option B is correct
And, the rest of the options would be wrong
And, the same would be relevant
The model shows how the Sun fuses two nuclei of hellum-3 into beryllium-6. Since beryllium-6 is unstable, it will decay into smaller nuclei.
What additional product completes the model?
O A Helium-4
OB Helium-8
o C Carbon-4
OD Carbon-8
Answer:
A
Explanation:
I took the test
2. If you are sitting on the passenger side of a car driving down the
highway, name a frame of reference that indicates you are NOT moving?
Answer:
The building are not getting farther and farther away, road signs, exits, other cars
Explanation:
PLEASEEEE HELP
Blue light of wavelength 435 nm
enters diamond (n = 2.42). What
is the wavelength of the light in
diamond?
(Unit = nm)
Answer:
Wavelength of light in diamond λ2 = 179.75 nm (Approx.)
Explanation:
Given:
Blue light of wavelength λ1 = 435 nm
n2 in diamond = 2.42
Find:
Wavelength of light in diamond λ2
Computation:
Since the wavelength is smaller, the frequency stays constant. The frequency of vibrations does not shift when they pass from one source to the next.
So,
n1λ1 = n2λ2
(1)(435) = (2.42)λ2
Wavelength of light in diamond λ2 = 179.75 nm (Approx.)
Answer:
180
Explanation:
got it right on acellus
A car is moving along a road. What force between the tyres and the road makes the car stop? Tick the correct box. Air Resistance, Gravity, Friction or weight?
Answer:All the forces are acting. The force due to which the car stops that is between road and tire is "friction".
Explanation:
Waldo needs to know how much force to apply in order to move a 4000-kg object at 2 m/S2. Which law should he refer to
Answer:
Newton's second law of motion?
A fruit basket of mass 44.5 kg weighs approximately how much in newton? (Answer should have a number and a proper unit) *
Answer:
445N
Explanation:
F=mg
m=44.5kg
g=10m/s2
F=44.5 * 10
=445N
After the collision, car 1 has a final velocity of 6m/s south. What is the final velocity of car2?
a) 35m/s north
b) 35m/s south
c) 81 m/s north
d) 81 m/s south
Can you describe how and why the molecules move from one side to the other?
The molecules move from one side to another across the concentration gradient by breaking weaker bonds among the atom into stronger bonds. This is done to decrease the overall kinetic energy to become a more stable molecule.
The kinetic strength of the molecules consequences in random movement, causing diffusion. In simple diffusion, this method proceeds without the useful resource of a transport protein. it is the random motion of the molecules that reasons them to move from a place of excessive attention to a place with decreased awareness.
The molecules in a gas, a liquid, or a strong are in consistent movement due to their kinetic electricity. Molecules are in steady movement and collide with each different. those collisions cause the molecules to move in random guidelines. over time, however, greater molecules may be propelled into the less concentrated place.
The majority of the molecules flow from better to decrease awareness, although there can be some that circulate from low to excessive. the general (or net) motion is consequently from high to low concentration.
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Un atleta tiene en un instante dado una velocidad de 4 m/s. Si a partir de ese instante y durante 2 s adquiere un MRUA con una aceleración de 3 m/s2. Calcula la velocidad que alcanza al cabo de esos 2 s.
Answer:
Velocidad final, V = 8 m/s
Explanation:
Dados los siguientes datos;
Velocidad inicial, u = 4 m/s
Aceleración, a = 2 m/s²
Tiempo, t = 2 segundos
Para encontrar la velocidad final (v), usaríamos la primera ecuación de movimiento;
V = u + at
Sustituyendo en la fórmula, tenemos;
V = 4 + 2*2
V = 4 + 4
Velocidad final, V = 8 m/s
what type of beetle is this?
A spherical conducting shell has charge -5 C. A particle with charge -8 C is placed at the center of the cavity. The charges (in C) on the inner surface and on the outer surface of the shell, respectively, are:
Answer:
Explanation:
The charge of - 5C will be spread on the outer surface of the shell . The presence of - 8C charge at the Centre will create + 8C charge on the inner surface and - 8C charge on the outer surface . The result is that the total charge on the outer surface of the shell will be - 5C + - 8C = - 13C and the inner surface will have charge of + 8C . + 8C charge will be locked to centrally situated - 8C charge and will not be neutralized by negative charge of outer surface .
HOW TO ANSWER THIS QUESTION PLEASE
Answer:
radioactive decay is a random processuse long tongsExplanation:
Quantum theory has taught us that virtually everything to do with the nature of matter in the universe is a random process. The decay of atomic nuclei is something that makes that randomness "visible" with appropriate instrumentation. As such, the rate of decay will vary over the "short" term. Consequently, it is not surprising to see a variation of a few counts in an activity measurement over a period of a few minutes.
__
Safety with respect to radioactive materials involves staying as far away from them as possible. The use of long tongs for handling would be appropriate.
Answer:
Radioactive decay is a long proxyUse long tongs↔ for safety precautions the scientist should used this upon working with radioactive materials in a laboratory.
1. Which term is the name given to the underwater mountains in the
middle of oceans? *
mid-ocean crust
mid-ocean mountas
mid-ocean ridges
mid-ocean basins
Answer:
The name given to the underwater mountains in the middle of oceans is;
Mid-ocean ridges
Explanation:
Mid-ocean ridges, also known as mid-oceanic ridge is a mountain range made by plate tectonics under the water.
The magma created at a divergent boundary where two tectonic plates meet due to the rise of convection currents in the Earth's mantle which is beneath the oceanic crust results in the uplifting of the ocean floor.
Light waves Group of answer choices are not electromagnetic radiation. do not require a medium. can not travel in a vacuum. do not travel in straight lines from the source.
Answer:
do not require a medium
Explanation:
Light waves can be regarded as electromagnetic waves and it transverse in nature, no medium material is required to pass through. Light wave can travel through vacuum and it's ray can travel in straight lines even from point source. Light convey energy in perpendicular direction to electric field as well as magnetic field.
ASAP PLEASE HELP WITH THIS 1.Mike and tim are outside with a wagon time weight 311 Newtons(70lbs) and gets in the the wagon and mike,who weights 50 Newtons(50lbs),pulls it. As mike pulls it, he accelerates until reaching a constant speed. After stopping, Mike and Tim switch places . Tim now pulls mike in the wagon, accelerating from stop to a constant velocity. Now, Tim may be bigger then mike but mike was riding in the wagon when it had the greatest acceleration during start up? Why? Use Newtons second law of motion to explain.
2. Now Sare comes along, and she is the exact same size as Mike. However, she is even stronger then mike When she pulls mike in the wagon, she pulls with a greater force than when mike pulls her. Now who is in the wagon when it has the greatest acceleration? Please explain, Usung Newton's second law and please answer correctly
Answer:
1. Mike was riding in the wagon when it had the most acceleration because his light weight compared to Tim's weight required the least effort to move
2. Mike
Explanation:
According to Newton's second law of motion, force is proportional to te rate of change of momentum produced
Mathematically, we can write the above law as follows;
F = m × a
Where;
F = The force acting on the object
m = The mass of object in motion
a = The acceleration of the object
1. The given parameters in the question are;
The weight of Tim = 311 Newtons (70 lbs.)
The weight of Mike = 50 Newtons (50 lbs.)
The minimum force required to pull the wagon to constant speed = The weight of the wagon
With the assumption that the wagon has very little weight, we have
Therefore, when Tim gets in the wagon, the force, 'F' applied by Mike to pull the wagon to constant speed = Mass of Tim, m × Acceleration of the cart, a
Given that mass is proportional to weight, we can write;
Force from mike, Tim on the wagon F₁ = 311 N × a₁
Similarly when they switched places, we have;
Force from Tim, Mike on the wagon = F₂ = 50 N × a₂
Therefore, for the same force, F₁ = F₂ = F, we have;
a₁ = F₁/(311 N) = F/(311 N)
a₂ = F₂/(50 N) = F/(50 N)
By fraction of numbers, F/(50 N) > F/(311 N) > N), therefore, a₂ > a₁
The acceleration of the wagon when Mike was on the wagon will be more than the acceleration of the wagon when Tim gets in the wagon because for the same applied force, the weight of Mike offer less resistance to move
2. Given that Sare and Mike have the same weight of 50 N each let F₃ represent the force with which she pulls Mike in the wagon, and F₁ represent the force with which Mike pulls her while she is on the wagon, we are also given that F₃ > F₁
By Newton's second law of motion, we have;
a₃ = F₃/(50 N) and a₁ = F₁/(50 N)
From F₃ > F₁, we have;
F₃/(50 N) > F₁/(50 N)
Therefore;
a₃ > a₁
The acceleration of the wagon when Mike is being pulled by Sare, a₃, is greater than the acceleration of the wagon when Sare is pulled by Mike
Therefore, Mike is on the wagon when it has the greatest acceleration.
Calculate the pressure exerted on the ground by a boy of a mass 60 kg if he stands on one foot.the area of the sole of his shoe is 150cm²
Answer:
40 Kpa
Explanation:
150 cm2 = 0.015 m2
[tex]p \: = \frac{mg}{ a} = 40000[/tex]
What are two ways fission is used in the real world.
Answer:
germ cleaning
and getting up cooking grease
Explanation: