Answer:
The momentum, ΔP, and therefore, kinetic energy given to the ball in a serve is the result of the product of the tension force, 'F', in the string and the time of contact, Δt, between the ball and the string
ΔP = F × Δt
Explanation:
The impulse, ΔP, is the produce of the force, 'F', applied to a body for a given period of time, Δt', that gives motion to the body, and it is equal to the change of momentum of the body
ΔP = F × Δt
The momentum, 'P', of a body is the product of the mass, 'm', of the body and its velocity, 'v'
P = m × v
Tension is the axial pulling force of a string
T = Axial Force, F[tex]_{axial}[/tex]
The tension used in Tennis Racket strings is between 40 to 65 lbs.
When high tension is used in the string, the string is taut, and the contact duration between the Racket string and the ball is minimal, and the player needs to use more force to obtain a high momentum, and therefore, energy in the ball, which reduces control, and increase stress, as force is more emphasized
When low tension is used in the string, the Tennis Racket strings are more elastic. During a serve, the ball pushes the strings further back into the racket, such that the ball spends more time in contact with the string, (Δt is larger), and therefore, the impulse, F·Δt = ΔP, given to the ball is larger, therefore, the ball has a larger change in momentum, and therefore more energy in the intended direction.
However, a very slackened string will increase the increase area and time (large Δt) of contact of the ball and the racket such that the force given to the ball, F = ΔP/(large Δt) is reduced and therefore reduce the likelihood of gaining points from a serve against an opponent with a much forceful return of a serve.
A decibel measures the _____________ of sound.
A.pitch
B,frequency
C.loudness
D.amplitude
1. What is the magnitude of the force on a charge of +40 μC that is 0.6 m from a charge of - 80 μC?
Answer:
The magnitude of the force is 79.893 N.
Explanation:
The magnitude of the electrostatic force between the two particles is determined by Coloumb's Law, whose formula is:
[tex]F = \frac{\kappa \cdot |q_{A}|\cdot |q_{B}|}{r^{2}}[/tex] (1)
Where:
[tex]\kappa[/tex] - Electrostatic constant, in newtons-square meters per square coulomb.
[tex]q_{A}, q_{B}[/tex] - Electric charges, in coulombs.
[tex]r[/tex] - Distance, in meters.
If we know that [tex]\kappa = 8.988\times 10^{9}\,\frac{N\cdot m^{2}}{C^{2}}[/tex], [tex]q_{A} = +40\times 10^{-6}\, C[/tex], [tex]q_{B} = - 80\times 10^{-6}\, C[/tex] and [tex]r = 0.6\,m[/tex], then the magnitude of the force is:
[tex]F = \frac{\kappa \cdot |q_{A}|\cdot |q_{B}|}{r^{2}}[/tex]
[tex]F = 79.893\,N[/tex]
The magnitude of the force is 79.893 N.
A 20 g block of ice is cooled to −65 ◦C. It
is added to 570 g of water in an 76 g copper
calorimeter at a temperature of 26◦C.
Find the final temperature. The specific
heat of copper is 387 J/kg ·
◦C and of ice is
2090 J/kg ·
◦C . The latent heat of fusion of
water is 3.33 × 10^5
J/kg and its specific heat
is 4186 J/kg ·
◦C .
Answer in units of ◦C.
Answer:
The final temperature is approximately 23.55°C
Explanation:
The given parameters are;
The mass of the ice block, m₁ = 20 g
The initial temperature of the block, T₁ = -65°C
The mass of the water to which the block is added, m₂ = 570 g
The mass of the copper container containing the water, m₃ = 76 g
The initial temperature of the water and the copper, T₂ = 26°C
The specific heat capacity of copper, c₃ = 387 J/(kg·°C)
The specific heat capacity of ice, c₄ = 2,090 J/(kg·°C)
The latent heat of fusion of ice, l = 3.33 × 10⁵ J/kg
The specific heat capacity of water, c₁ = 4,186 J/(kg·°C)
We have;
ΔQ = m₁·c₁·ΔT + m₁·l = m₂·c₂·ΔT + m₃·c₃·ΔT
Therefore, we get;
20 × 2,090 × -65 + 20 × 3.33 × 10⁵ + 20 × T × 4,186 = 570 × 4,186 × (26 - T) + 76 × 387 × (26 - T)
Using a graphing calculator, we get;
83720·T + 3943000 = 62801232 - 2415432·T
The final temperature, T ≈ 23.55 °C
Please Help Me!!!
Water is a colorless and odorless liquid. It can exist in solid, liquid, and gas states. It boils at 100 degrees C and melts at 0 degrees C.
Which option best describes this information?
A.
These are the physical properties of water.
B.
These are the chemical properties of water.
C.
These are the physical changes water undergoes.
D.
These are the chemical changes water undergoes.
E.
These are the molecular changes water undergoes.
Answer:
There are the molecular changes water undergoes
Highlight two factors which shows that heat from the sun does reach the earth's surface by convection.
radiation
when the suns radiation fall on the earth and its objects they receive heat energy and hence get heated. Thus the suns heat reaches the earth by. the process of radiation
Absence of medium is the factor which shows that heat from the sun does reach the earth's surface by convection.
The heat of the sun reaches the earth only through radiation because radiation does not require any medium for the transfer of energy but convection and conduction required a medium to transfer heat energy.
We know that there is no medium present in vacuum so convection and conduction are impossible in a vacuum that's why the sun's heat does not reach the earth by conduction or convection.
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HELP pleaseee which nucleus completes the following equation?
Answer:
its D
Explanation:
i just got it correct on a. p. e. x. :)
7. An object can be accelerating even if its speed is
constant if it
(a) comes to a stop
(b) is not possible
(C) changes direction
(d) moves in a straight line
Answer:
I think that the answer might be d
Answer:
D
Explanation:
If a car is moving very fast in a straight road or a highway in such a way that it has reached its limits as soon as it is going that fast it can break it limit
Is this right? Please help me ITS SOCIOLOGY
Which of the following statements is true about absolute zero?
It is the point at which electrons separate from the nucleus of atoms.
It is the point at which electrons separate from the nucleus of atoms.
It is theoretically the point at which all particle motion stops.
It is theoretically the point at which all particle motion stops.
It occurs at 273 degrees Kelvin.
It occurs at 273 degrees Kelvin.
It is the point at which protons separate from neutrons in the nucleus
Answer:
It is the point at which electrons separate from the nucleus of atoms. It is the point at which electrons separate from the nucleus of atoms. It is theoretically the point at which all particle motion stops. ... It occurs at 273 degrees Kelvin. ... It is the point at which protons separate from neutrons in the nucleus.
Explanation:
A firework is launched with a force of 700 N and a momentum of 200 kg-m/s. How much time before is explodes?
Answer:
t = 0.28 seconds
Explanation:
Given that,
Force acting on a firework, F = 700 N
The momentum of the firework, p =200 kg-m/s
We need to find the time before it explodes. Ket the time be t. We know that, the rate of change of momentum is equal to external frce. So,
[tex]F=\dfrac{P}{t}\\\\t=\dfrac{P}{F}\\\\t=\dfrac{200}{700}\\t=0.28\ s[/tex]
So, the required time is equal to 0.28 seconds.
What specific type of tide has the smallest difference between high and low tide?
Answer: Neap tides
Explanation: Neap tides are tides that have the smallest tidal range, and they occur when the Earth the Moon, and the Sun form a 90o angle. They occur exactly halfway between the spring tides when the Moon is at first or last quarter.
Why must the Moon travel more than a full orbit around the Earth for the full moon to be complete?
Answer:
The difference between the sidereal and synodic months occurs becuase as our moon moves around the earth, the earth also moves around our sun. Our moon must travel a little farther in its path to make up for the added distance and complete the phase cycle.
Explanation:
Hope this helps.
Which of the following ways of writing 1000w is incorrect?
1) 1 kW
2) 1 x 10³ W
3) 10 x 10³ W
4) 1.0 x 10³ W
Answer:
the third one is incorrect
Explanation:
10 x 10³= 10^1 x 10^3 = 10^4
What are examples of changes in people, animals, or objects that would help you make a claim about their age? NO LINKS OR YOURE GETTING REPORTED. Thanks
It’s Earth Science
Answer:
An example of changes in people based on their age, are mood changes,playfulness and as of objects you can say old or broken, animals can use the same reference as humans, the more mature you are can suggest your older, such as the more worn down your are based on a object
A boy who is riding his bicycle, moves with an initial velocity of 5 m/s. ten second later, he is moving at 15 m/s. what is his acceleration
[tex]\Large {{ \sf {Question :}}} [/tex]
A boy who is riding his bicycle, moves with an initial velocity of 5 m/s. Ten second later, he is moving at 15 m/s. What is his acceleration?[tex]\Large {{ \sf {Given :}}} [/tex]
Initial Velocity (u) - 5 m/sFinal Velocity (v) - 15 m/sTime (t) - 10 sec[tex]\Large {{ \sf {Formulae :}}} [/tex]
If the velocity of an object changes from an initial value u to the final value v in time t, the acceleration a is, [tex]a \: = \frac{v - u}{t} [/tex][tex]\Large {{ \sf {Step-by-step explanation :}}} [/tex][tex]a \: = \frac{v - u}{t} \\ or \: \: a = \frac{(15 - 5)}{10} m \: s^{ - 2} \\ or \: \: a \: = \frac{10}{10}m \: s^{ - 2} \\ or \: \: a = 1m \: s^{ - 2} [/tex]
[tex]\Large {{ \sf {Answer :}}} [/tex]
His acceleration is [tex]1m \: s^{ - 2} [/tex]how is momentum of an object related to stopping distance
Answer:
To stop a car must lose its momentum and its kinetic energy. ... If the forces on two cars are equal then the greater the kinetic energy the greater the distance before stopping. But there will be a relationship to the momentum because momentum and mass are both related to the kinetic energy.
Based on the graph, describe how momentum changes with time for an object in free fall. If you can help, I would be so grateful.
Which statement best summarizes the development of the atomic theory over time?
Answer:
electrons move around nucleus in specific regions
We have that the correct statement that summarizes atoms over time will be
The discovery of new evidence resulted in changes to the atomic theory.
Option B
Generally
The Image shows that in the early 1800 the knowledge of atom was limited and it increased over time and by 1920 it had gone through a 4 stages of modifications to the atomic model
Atoms are solid spheresElectrons are attached to atom surfaceElectrons move around in the nucleus in a specificRapid motion of electrons in the cloudTherefore the correct statement that summarizes atoms over time will be
The discovery of new evidence resulted in changes to the atomic theory
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Milk is a very weak acid. What might its pH value be ?
Answer:
pH value is between 6.5 and 6.8
Explanation:
Explanation:
Milk fresh from the cow typically has a pH between 6.5 and 6.7. The pH of milk changes over
PLEASE ANSWER THIS ASAP I WILL MARK YOU THE BRAINLIEST The actual subject is Science but they dont have that as a option in pick a subject
Explanation:
speed : • how fast an object changes position
• miles per hour.
• distance/time.
velocity: • speed in a direction
• miles per hour North
• distance/ time in a direction
Two resistors, 2.50 Ω and 4.95 Ω, are wired in series to a 12.00 V battery. What is the equivalent resistance of the circuit?
Answer:
7.45 Ω
Explanation:
From the question given above, the following data were obtained:
Resistor 1 (R₁) = 2.50 Ω
Resistor 2 (R₂) = 4.95 Ω
Voltage (V) = 12 V
Equivalent Resistance (Rₑq) =?
Since the resistors are in series arrangement, the equivalent resistance can be obtained as follow:
Rₑq = R₁ + R₂
Rₑq = 2.5 + 4.95
Rₑq = 7.45 Ω
Therefore, the equivalent resistance is 7.45 Ω
A meter is larger than a
A.
hectometer
B.
kilometer
C.
decimeter
D.
dekameter
The 4kg head of a sledge hammer is moving at 6m/s when it strikes a chisel, driving it into a log. The duration of the impact (or the time for the sledge hammer to stop after contact) is 0.0020s. Find the time average of the impact force
Answer:
The average impact force is 12000 newtons.
Explanation:
By Impact Theorem we know that impact done by the sledge hammer on the chisel is equal to the change in the linear momentum of the former. The mathematical model that represents the situation is now described:
[tex]\bar F \cdot \Delta t = m \cdot (v_{2}-v_{1})[/tex] (1)
Where:
[tex]\bar F[/tex] - Average impact force, in newtons.
[tex]\Delta t[/tex] - Duration of the impact, in seconds.
[tex]m[/tex] - Mass of the sledge hammer, in kilograms.
[tex]v_{1}[/tex], [tex]v_{2}[/tex] - Initial and final velocity, in meters per second.
If we know that [tex]\Delta t = 0.0020\,s[/tex], [tex]m = 4\,kg[/tex], [tex]v_{1} = -6\,\frac{m}{s}[/tex] and [tex]v_{2} = 0\,\frac{m}{s}[/tex], then we estimate the average impact force is:
[tex]\bar F = \frac{m\cdot (v_{2}-v_{1})}{\Delta t}[/tex]
[tex]\bar F = 12000\,N[/tex]
The average impact force is 12000 newtons.
A boy who is riding his bicycle, moves with an initial velocity of 5 m/s. ten second later, he is moving at 15 m/s. what is his acceleration
Answer:
1 m/s²
Explanation:
From the question,
Using
a = (v-u)/t.................... Equation 1
Where a = accelartion of the bicycle, v = Final velocity, u = initial velocity, t = time.
Given: v = 15 m/s, u = 5 m/s, t = 10 s
Substitute these values into equation 1
a = (15-5)/10
a = 10/10
a = 1 m/s²
Hence the acceleration of the bicycle is 1 m/s²
A horizontal spring is lying on a frictionless surface. One end of the spring is attached to a wall, and the other end is connected to a movable object. The spring and object are compressed by 0.065 m, released from rest, and subsequently oscillate back and forth with an angular frequency of 11.3 rad/s. What is the speed of the object at the instant when the spring is stretched by 0.048 m relative to its unstrained length
Answer:
Explanation:
Given that:
angular frequency = 11.3 rad/s
Spring constant (k) = [tex]= \omega^2 \times m[/tex]
k = (11.3)² m
k = 127.7 m
where;
[tex]x_1[/tex] = 0.065 m
[tex]x_2[/tex] = 0.048 m
According to the conservation of energies;
[tex]E_1=E_2[/tex]
∴
[tex]\Big(\dfrac{1}{2} \Big) kx_1^2 =\Big(\dfrac{1}{2} \Big) mv_2^2 + \Big(\dfrac{1}{2} \Big) kx_2^2[/tex]
[tex]kx_1^2 = mv_2^2 + kx_2^2[/tex]
[tex](127.7 \ m) \times 0.065^2 = v_2^2 + (127.7 \ m) \times 0.048^2[/tex]
[tex]0.5395325 = v_2^2 +0.2942208 \\ \\ 0.5395325 - 0.2942208 = v_2^2 \\ \\ v_2^2 = 0.2453117 \\ \\ v_2 = \sqrt{0.2453117} \\ \\ \mathbf{ v_2 \simeq0.50 \ m/s}[/tex]
Two waves, each with an amplitude of 0.5m are superimposed with constructive interference such that they are in phase. Describe the resultant amplitude
The resultant amplitude of the two waves is 1.0m
Interference occurs when two or more waves are superimposed over each other. These waves can either be destructive or constructive in nature. If the waves are superimposed with constructive interference such that they are in phase, the resultant amplitude will be the sum of the amplitude of both waves.Resultant amplitude = 0.5m + 0.5m
Resultant amplutude = 1.0m
Hence the resultant amplitude of the two waves is 1.0m
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PLEASE ANSWER THIS ASAP I WILL MARK YOU THE BRAINLIEST The actual subject is Science but they dont have that as a option in pick a subject
Answer:
Third option
Explanation:
To calculate meters per second you divide the distance by the time.
it's 8m/s
A toy gun uses a spring to shoot plastic balls (m = 50 g). The spring is compressed by 3.0 cm. Let k=2.22 × 105 N/m. (a) Of course, you have to do some work on the gun to arm it. How much work do you have to do? (b) Suppose you fire the gun horizontally. How fast does the ball leave the gun? (c) Now suppose you fire the gun straight upwards. How high does the ball go?
Answer:
Explanation:
Given that:
mass of the plastic ball = 50 g = 50 × 10⁻³ kg
spring constant (k) = 2.22 × 10⁵ N/m
compression of spring (x) = 3.0 cm = 3 × 10⁻² m
a) Work done:
[tex]= \dfrac{1}{2}kx^2 \\ \\ = \dfrac{1}{2}\times 2.22 \times 10^{5}\times (3 \times 10^{-2})^2 \\ \\ = 99.9 \ J[/tex]
b) When the gun is fired horizontally;
In the spring, the potential energy is changed to kinetic energy.
i.e.
[tex]\implies \dfrac{1}{2}kx^2 = \dfrac{1}{2}mv^2 \\ \\ 2.22 \times 10^5 \times (3\times 10^{-2}) ^2 =50 \times 10^{-3} \times v^2\\ \\ \mathbf{v= 63.2 m/s}[/tex]
c) The max height the bullet will reach if the gun is being shot upward is:
[tex]H_{max}= \dfrac{v^2}{2g} \\ \\ H_{max}= \dfrac{63.2^2}{2\times 9.8}[/tex]
[tex]\mathbf{H_{max}= 203.9 \ m}[/tex]
Please help me look at the image below
Which statement is true of an alpha particle?
A. It is electromagnetic radiation, not a true particle.
B. It is an electron.
C. It is the largest decay particle
D. It is a particle that travels at the speed of light.
Answer:
Atoms are made up of various parts; the nucleus contains minute particles ... neutrons, and the atom's outer shell contains other particles called electrons. ... Physical Forms of Radiation; Radioactive Decay; Nuclear Fission; Ionizing Radiation ... of high-energy waves that can travel great distances at the speed of light and ...
Explanation:
The true statement of an alpha particle is it is an electron. The correct option is B.
What is an alpha particle?The alpha particle are composite particles which consists of two protons and two neutrons tightly bonded together. They are ejected from the inside the nucleus of heavy radioactive particles, also called alpha decay.
Atoms are made up electrons orbiting in outer shells, protons and neutrons in the nucleus. The radioactive particle emit highly ionized radioactive rays which ionize electrons emitting alpha particle.
Thus, the correct option is B.
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