42 POINTS!!!!
are players trying to minimize or maximize friction when playing volleyball?
None
Friction in Volleyball
Frication plays a huge role in every aspect of our lives; it can play a negative or positive role. In volleyball there are various types of friction that have positive influences on the way the game is played and there are others that play a negative role in the way the game is played.
Positive friction in volleyball.
In volleyball the aim of the game is to strike a ball into play that your opponent cannot return or finds it difficult to return. A friction force that makes this possible is the friction of the air on the ball, for example when a player hits a ball with topspin into play, the friction of the air on the ball makes it spin faster than it otherwise would. Topspin makes a ball harder to pick-up and pass to the setter.
Another force that is present is the ball itself, if there was no friction it would be virtually impossible to pass set, or hit the ball, the ball would just slip through your arms or hands.
When jumping a player also uses the frictions of their feet on the floor to gain a higher jump to strike the ball at maximal height, if this didn't exist players would be slipping and sliding around all over the court.
Negative friction in volleyball.
Friction also plays a negative part in the game of volleyball, when a player dives for a ball the friction of the court on their skin causes court burn or friction burn. Although the friction of the rubber soles of shoes on the court is a positive it can also be a negative, if there is too much friction players can become injured from the sudden stopping that the friction can cause. Some injuries that can result from this would be hyperextensions of the knees and or ankle injuries.
The illustration in figure below shows a uniform metre rule weighing 30 N pivoted on a wedge placed under the 40 cm mark and carrying a weight of 70 N hanging 2 from the 10 cm mark. The ruler is balanced horizontally by a weight W hanging from the 100 cm mark. Calculate the value of the weight W.
Answer:
W = 30 N
Explanation:
Applying the summation of torques about the wedge for equilibrium, taking the clockwise direction as negative. Since the ruler is balanced horizontally about the wedge. Therefore, the summation of all torques acting about the wedge must be equal to zero.
[tex](70\ N)(40\ cm - 10\ cm)-(30\ N)(50\ cm-40\ cm)-(W)(100\ cm - 40\ cm) = 0\\W(60\ cm) = (70\ N)(30\ cm)-(30\ N)(10\ cm)\\\\W = \frac{1800\ N.cm}{60\ cm}[/tex]
W = 30 N
What is density?
A- How much space an object takes
up
B- The amount of matter in a certain
amount of space
C- How much water an object
displaces
D- How much an object is affected by
gravity
Answer:
B- The amount of matter in a certain
amount of space
Explanation:
Density is the amount of matter an object has in a certain space. To find density, divide the mass of an object by the volume of an object.
Answer:
C- How much water it displaces
Explanation:
Describe the net transfer of thermal energy and any changes in temperature When a metal block at 300Ak is placed in water at 15°C
Answer:
Q_c = Q_abs
Explanation:
You are asked to describe the process when placing a hot block in cold water.
The first thing to do is put all the quantities in the same units
block temperature T_bloque = T_h = 300 K = 300 -273 = 27ºC
water temperature T_water = T_c = 15ºC
* initially the block cools down decreasing its temperature
* the water temperature increases
* the equilibrium is established when the thermal energy of the two bodies is equal, therefore they have the same temperatures T_f
* Conservation of energy requires that the energy released by the hot block is equal to the energy absorbed by the cold body (water)
transferred thermal energy Q_c = m_block ce_block (T_h-T_f)
absorbed thermal energy Q_abs = m_agua ce_agua (T_f - T_c)
* if we subtract the energy transferred and the absorbed gives zero, therefore the net energy transferred is zero
Q_c = Q_abs
PLEASE HELPPPPPPPPPP
Answer:
Peer Review
Explanation:
When scientist check other scientists the process is dubbed "peer review".
Determine the resistance of 100m of copper cable whose cross-sectional area is 1.5mm2
A 1500 kg car accelerats from 55.0 m/s to 90.0 m/s. Calculate the impulse experienced by the car
Answer:
The impulse experienced by the car is 52,500 kg.m/s.
Explanation:
Given;
mass of the car, m = 1500 kg
initial velocity of the car, u = 55 m/s
final velocity of the car, v = 90 m/s
The impulse experienced by the car is the change in linear momentum, calculated as follows;
J = ΔP = mv - mu
ΔP = m(v - u)
ΔP = 1500(90 - 55)
ΔP = 52,500 kg.m/s
Therefore, the impulse experienced by the car is 52,500 kg.m/s.
Pierce conducts an experiment in which waves collide in a way that the energy increases. What has occurred? refraction reflection constructive interference destructive interference
Answer:
constructive interference.
Explanation:
Electromagnetic waves is a propagating medium used in all communications device to transmit data (messages) from the device of the sender to the device of the receiver.
Generally, the most commonly used electromagnetic wave technology in telecommunications is radio waves.
Radio waves can be defined as an electromagnetic wave that has its frequency ranging from 30 GHz to 300 GHz and its wavelength between 1mm and 3000m.
In this scenario, an experiment is conducted by Pierce in which waves collide in a way that the energy increases. Thus, this is an example of constructive interference i.e constructive interference has occurred.
An interference occurs when two pair of waves such as sound and light waves pass through each other i.e crossing each other's path while traveling through the same medium or space.
Answer:
constructive interference.
Explanation:
Eye at the lowest radiated power of 1,2 x10 x (- 17) W. Determine how many photons of light with a wavelength of 500nm fall on the retina of the eye every second
Answer:
[tex]\frac{n}{t} = 30\ photons/s[/tex]
Explanation:
The radiated power can be given in terms of the wavelength as follows:
[tex]Rasiated\ Power = \frac{nE}{t} = \frac{nhc}{\lambda t}[/tex]
where,
Radiated Power = 1.2 x 10⁻¹⁷ W
n = no. of photons = ?
h = plank's constant = 6.625 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength = 500 nm = 5 x 10⁻⁷ m
t = time
Therefore,
[tex]1.2\ x\ 10^{-17}\ W = \frac{n(6.625\ x\ 10^{-34}\ J.s)(3\ x\ 10^8\ m/s)}{(5\ x\ 10^{-7}\ m)(t) }\\\\\frac{n}{t} = \frac{1.2\ x\ 10^{-17}\ W}{3.975\ x\ 10^{-19}\ J}\\\\\frac{n}{t} = 30\ photons/s[/tex]
Heat is a measure of how much energy flows from __________ objects to _________ objects. It _________ the same thing as temperature.
Answer:
heat is a measure of how energy flows from hot to Cold object. It means the same thing as temperature
Heat is a measure of how much energy flows from hotter objects to cold objects. It flow the same thing as temperature.
What is Temperature ?Temperature is a physical quantity which measures hotness and coldness of a body. Temperature measures the degree of vibration of molecule in a body. Temperature is measured in centigrade (°C), Fahrenheit (°F) and Kelvin (K) in which Kelvin (K) is a SI unit of temperature. Absolute scale of temperature means Kelvin scale of temperature. relation between Kelvin(K) and centigrade (°C), °C= K - 273.15 from equation, 273.15 K means 0 °C, which is freezing point of water (ice). when we give temperature to the body, its molecule or atom absorbs thermal energy and vibrate about their mean position. Amplitude of vibration get increases as we go on increasing temperature and for higher temperature force of attraction between molecules gets weaker. Hence for higher temperature, due to weaken the force of attraction between molecule, solid goes into liquid state. and further increase in temperature liquid goes into gaseous state.
Heat flows from high temperature to low temperature
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The eye of the Atlantic giant squid has a diameter of 3.50 × 10^2 mm. If the eye
is viewed in a concave mirror with a radius of curvature equal to the diameter
of the eye and the eye is 0.800 × 10^3 mm from the mirror, how far is the image
from the mirror? What is the size of the image? Is the image real or virtual?
Answer:
q = 224 mm, h ’= - 98 mm, real imagen
Explanation:
For this exercise let's use the constructor equation
[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 the image respectively.
In a mirror the focal length is
f = R / 2
indicate us radius of curvature is equal to the diameter of the eye
R = 3,50 10² mm
f = 3.50 10² /2 = 1.75 10² mm
they also say that the distance to the object is p = 0.800 10³ mm
1 / q = 1 / f - 1 / p
1 / q = 1 / 175 - 1 /800
1 / q = 0.004464
q = 224 mm
to calculate the size let's use the magnification ratio
m = [tex]\frac{h'}{h} = - \frac{q}{p}[/tex]
h '= [tex]- \frac{q}{p} \ h[/tex]
h ’= - 224 350 / 800
h ’= - 98 mm
in concave mirrors the image is real.
define one ampere current electricity
Rogan claims that he can run 8 miles per hour. Use the speed formula to determine how many minutes it would take him to run one mile.
Answer:
he would have to run at a 7 and a half mile to get 8 miles in an hour
Explanation:
Answer:
7.5 minutes
Explanation:
We know that there are 60 minutes in an hour. So, we can say that Rogan can run 8 miles per 60 minutes. Now, we can create an equation to solve for how many minutes it would take per mile.
8/60 = 1/x
x = 7.5
So, it would take Rogan approximately 7.5 minutes to travel 1 mile.
What is the velocity of position A and B?
answer please
Answer:
A = 15 m/s , B = 18.75 m/s
Explanation:
from the velocity is equal to zero ( at rest ) , you see that velocity is increasing by 3.75 m/s for each second.
I hope that it's a correct answer.
Make a list of all the possible human sources of carbon dioxide
Answer:
car fuel
production waste (like producing plastic, car, materials)
breathing
landfill
cement production
deforestation (cutting down trees)
burning of fossil fuels (coals, oil, natural gases)
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Explanation:
Is this statement correct that all charged particles experience same force in uniform electric field
Answer:
No the statement is incorrect.
Explanation:
Mathematically, force F experience of a charge particle of magnitude q in an uniform electric field E is given as
F = E/q
In uniform electric field is where the intensity of electric field remains same throughout. However, from the above equation it is clear that force experience by the charge particle also depends upon the magnitude of charge particle as well. So, with change in charge particles the force experienced by it also changes.
3. When you threw the ball upward at 40 m/s, how much time would have
passed from when you threw it to when you catch it? *
2 seconds
4 seconds
8 seconds
12 seconds
Explain the relationship between the distance between the string and your elbow and the effort required to lift the mass.
Answer:
Sorry I I’m a little lost
Explanation:
Answer:
hmm the relation ship would be bad 1 because its not cooperating because I would have to do allot of force to pick up the mass with a tiny string, what an idiot, 2nd the distance is far now that its not a good relationship
Explanation:
hope this helps old pal ( :
Is gravitational pull strengthened by distance?
I'm not sure but I think that if objects are closer (less distant), than the gravitational pull is stronger. I'm sorry if I couldn't really help I remember learning about this kind of.
what three types of electromagnetic waves carry most of the sun's energy that strikes Earth. Do Not Send Me A Link.
Answer:
The answer is C.
Answer:
The answer would be the second one I'm pretty sure.
Explanation:
i know this is easy but i’m am just not sure
Answer:
kinetic energy
Explanation:
vinegar and baking soda are composed of atoms which react to each other when mixed therefore they convert the potential energy inti kinetic energy.
How is the electroscope an example of a conductor?
Answer: Its in explanation.
Explanation:
Because the electroscope is made from conducting material, some of its electrons move up to the top of the electroscope to be near the charged rod when the rod is held close.
Answer:
Because it is made up of conducting materials
PLS HELP!!!! the image shows a chart to help!!
-The question is, "The following equations represents Chemical reactions. Which equation shows at the total mass during a chemical reaction stays the same?"
answer choice are:
A. equation 2
B. equation 1
C. equation 3
D. equation 4
A proton is moved so that its electric potential energy increases from 2.0 × 10-18 J to 6.0 × 10-18 J. The magnitude of the charge on a proton is 1.602 × 10-19 C.
The electric potential difference through which the proton moved, to the nearest whole number, is
V.
Answer:
25v
Explanation:
right on edge
A 50 KG girl on a swing is pushed with a net force of 200 N. What is the girl’s acceleration?
Answer:
a = 4 m/s2
Explanation:
Given: 200 N, 50 kg
To find: a
Formula: [tex]A = \frac{f}{m}[/tex]
Solution: To find a, divide the force by the weight
A = F ÷ m
= 200 ÷ 50
= 4 m/s²
Newtons are derived units, equal to 1 kg-m/s². In other words, a single Newton is equal to the force needed to accelerate one kilogram one meter per second squared.
A schoolbus accelerates to 65 mph and enters the freeway. It travels for 2.3 hours at that speed while on the freeway. What's the distance travelled on the freeway?
Answer:
The distance travelled on the freeway is 149.5 miles.
Explanation:
The school bus travels on the freeway at constant speed. According to the statement, we need to calculate the distance travelled by the vehicle by means of the following formula:
[tex]x = v\cdot t[/tex] (1)
Where:
[tex]x[/tex] - Traveled distance, in miles.
[tex]v[/tex] - Speed, in miles per hour.
[tex]t[/tex] - Time, in hours.
If we know that [tex]v = 65\,\frac{mi}{h}[/tex] and [tex]t = 2.3\,h[/tex], then the distance travelled by the school bus is:
[tex]x = v\cdot t[/tex]
[tex]x = \left(65\,\frac{mi}{h} \right)\cdot (2.3\,h)[/tex]
[tex]x = 149.5\,mi[/tex]
The distance travelled on the freeway is 149.5 miles.
what is the difference between atoms and ions
Answer:
[tex]{\huge\purple{\fbox{{࿐αɴѕωєя࿐}}}}[/tex]
[tex] \huge\red{\boxed{\mathfrak{Atoms}}}[/tex]
The smallest unit of an element.Not independent in solution.Atoms form molecules.Electrons and protons are equal.Unstable in nature.[tex] \huge\red{\boxed{\mathfrak{Ions}}}[/tex]
Single particle or collection of particles.Is independent in solution.Ions form electrovalent bond.Electrons and protons are unequal.Stable in nature.✏ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ
[tex] \huge\blue{ \mid{ \underline{ \overline{ \tt ꧁❣ RainbowSalt2222 ࿐ }} \mid}}[/tex]
Which statement is false?
A) The direction a magnet moves through a coil of wire determines the direction of the
electric current
B) The direction a coil of wire moves through a magnetic field determines the direction
of the electric current.
C) Current will flow through a wire as long as the magnetic field around the coil is
changing
D) Current will not flow though a wire if the magnet is outside the coil.
Answer:
D. Current with not flow through a wire if the magnet is outside the coil.
Explanation:
have a good day
The movement of the electrons caused by the magnetic field's pull on them causes an electric current to flow through a wire coil when it is passed over a stationary bar magnet, hence option D is correct.
What is a magnetic field?It is possible to think of the magnetic field as a scalar object with a single magnitude in space.
The magnetic field is described as a field around a magnet that exerts a magnetic force on electrically charged particles present in the magnetic field. Teslas are a unit of measurement for the magnetic field.
Magnetic fields, or vector fields, have an impact on electric currents, electric charges, and magnetic materials. In a magnetic field, a moving charge experiences an external force that is perpendicular to the magnetic field and has its own velocity.
Therefore, current will not flow through a wire if the magnet is outside the coil is a false statement.
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Help!!!
Where can the hoses be attached in order to provide water to a fire engine? (There may be more than one correct answer.)
house faucet
hydrant
generator
pumper truck
Answer:
Explanation:
Hydrant
can someone help?? 4/5
Answer: I may not have the awser but
Explanation: Try calculating 8.932 times
10^22 kg
Answer:
F = 2.68 x 10²³ N
Explanation:
The force between lo and Jupiter is given by Newton's Gravitational Formula:
[tex]F = \frac{Gm_1m_2}{r^2} \\[/tex]
where,
F = Force = ?
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ Nm²/kg²
m₁ = mass of lo = 8.932 x 10²² kg
m₂ = mass of Jupiter = 1.9 x 10²⁷ kg
r = distance between lo and Jupiter = 4.22 x 10⁸ m
Therefore,
[tex]F = \frac{(6.67\ x\ 10^{-11}Nm^2/kg^2)(8.932\ x\ 10^{22}\ kg)(1.9\ x\ 10^{27}\ kg)}{(4.22\ x\ 10^8\ m)^2}[/tex]
F = 2.68 x 10²³ N