The density of the cube of wood placed in the tub of water is determined as 700 kg/m³.
Specific gravity of the woodThe specific gravity of the wood is the fraction of the entire wood volume below water surface.
Height below water surface = 20 cm - 6 cm = 14 cm
S.G = 14 cm/20 cm
S.G = 0.7
Density of the woodThe density of the wood is calculated with respect to density of water.
S.G = ( density of wood) / (density of water)
0.7 = (density of wood) / (1000 kg/m³)
density of wood = 0.7 x 1000 kg/m³
density of wood = 700 kg/m³
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The measurement of cosmic distances was helped tremendously by the discovery, in the early part of the 20th century, that in Cepheid variable stars, the average luminosity was related to:
In the early 20th century, the average luminosity in Cepheid variable stars was related to: the period of time it takes to vary.
What is a cosmic distance?A cosmic distance can be defined as an accurate and precise measurement of the distance to celestial or astronomical objects such as:
GalaxiesStarsMoonSunIn the early 20th century, a discoery of the average luminosity in Cepheid variable stars was related by astronomers to the period of time it takes to vary and this helped tremendously in the measurement of cosmic distances.
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Estuaries are the place where rivers flow into the sea, and the freshwater they contain meets and mixes with salty seawater. question 2 options: true false
Answer:
true
Explanation:
i did the test
When an object in simple harmonic motion is at its maximum displacement, its____________ is also at a maximum.
When an object in simple harmonic motion is at its maximum displacement, its acceleration is also at a maximum.
Reason: The speed is zero when the simple harmonic motion is at its maximum displacement, however, the acceleration is the rate of change of velocity. The velocity reverses the direction at that point therefore its rate of change is maximum at that moment. thus the acceleration is at its maximum at this point
Hope that helps!
A 1,508 kg car rolling on a horizontal surface has a speed of 20.8 km/hr when it strikes a horizontal coiled spring and is brought to rest in a distance of 6.87 m. What is the spring constant (in N/m) of the spring
Answer:
Approximately [tex]1.79 \times 10^{5}\; {\rm N \cdot m^{-1}}[/tex], assuming friction between the vehicle and the ground is negligible.
Explanation:
Let [tex]m[/tex] denote the mass of the vehicle. Let [tex]v[/tex] denote the initial velocity of the vehicle. Let [tex]k[/tex] denote the spring constant (needs to be found.) Let [tex]x[/tex] denote the maximum displacement of the spring.
Convert velocity of the vehicle to standard units (meters per second):
[tex]\begin{aligned}v &= 20.8\; {\rm km \cdot h^{-1}} \times \frac{1000\; {\rm m}}{1\; {\rm km}} \times \frac{1\; {\rm h}}{3600\; {\rm s}} \\ &\approx 1.908\; {\rm m \cdot s^{-1}}\end{aligned}[/tex].
Initial kinetic energy ([tex]{\rm KE}[/tex]) of the vehicle:
[tex]\begin{aligned}\frac{1}{2}\, m \, v^{2}\end{aligned}[/tex].
When the vehicle is brought to a rest, the elastic potential energy ([tex]\text{EPE}[/tex]) stored in the spring would be:
[tex]\displaystyle \frac{1}{2}\, k\, x^{2}[/tex].
By the conservation of energy, if the friction between the vehicle and the ground is negligible, the initial [tex]\text{KE}[/tex] of the vehicle should be equal to the [tex]{\rm EPE}[/tex] of the vehicle. In other words:
[tex]\begin{aligned}\frac{1}{2}\, m \, v^{2} &= \frac{1}{2}\, k\, x^{2}\end{aligned}[/tex].
Rearrange this equation to find an expression for [tex]k[/tex], the spring constant:
[tex]\begin{aligned}k &= \frac{m\, v }{x^{2}}\end{aligned}[/tex].
Substitute in the given values [tex]m = 1508\; {\rm kg}[/tex], [tex]v \approx 1.908\; {\rm m\cdot s^{-1}}[/tex], and [tex]x = 6.87\; {\rm m}[/tex]:
[tex]\begin{aligned}k &= \frac{m\, v }{x^{2}} \\ &\approx \frac{1508\; {\rm kg} \times 1.908\; {\rm m\cdot s^{-1}}}{(6.87\; {\rm m})^{2}} \\ &\approx 1.79 \times 10^{5}\; {\rm kg \cdot m \cdot s^{-2} \cdot m^{-3}}\\ &\approx 1.79 \times 10^{5}\; {\rm N \cdot m^{-1}}\end{aligned}[/tex]
Hello people ~
Which of the following options are correct?
If a conductor has a potential V 4- 0 and there are no charges anywhere else outside, then _____
(a) there must not be charges on the surface or inside itself.
(b) there cannot be any charge in the body of the conductor.
(c) there must be charges only on the surface.
(d) there must be charges inside the surface.
The charge would be in equilibrium so there would be no charge in the body of the conductor.
Answer:
(b) there cannot be any charge in the body of the conductor
Answer:
B
Explanation:
Note the line that there is no charges anywhere else outside means the charge is placed in equilibrium position.
Hence there cannot be any charge in the body of conductor
As velocity____kinetic energy _____ and potential energy _____
Answer:
increases increases decreases
Explanation:
For an object falling from a height
Explain how sound waves are created and how they travel
Answer:
Sound is produced when an object vibrates, creating a pressure wave. This pressure wave causes particles in the surrounding medium (air, water, or solid) to have vibrational motion. As the particles vibrate, they move nearby particles, transmitting the sound further through the medium.
Explanation:
A 2.03 kg book is placed on a flat desk. Suppose the coefficient of static friction between the book and the desk is 0.602 and the coefficient of kinetic friction is 0.327 . How much force is needed to begin moving the book
Answer:
11.98 N
Explanation:
Normal force = mg = 2.03 * 9.81
coeff of static friction must be overcome for the book to begin moving
.602 = F / (2.03 * 9.81) = 11.98 N
A 1.10-kg block of wood sits at the edge of a table, 0.790 m above the floor. A 1.15×10−2-kg bullet moving horizontally with a speed of 700 m/s embeds itself within the block.
What horizontal distance does the block cover before hitting the ground?
Answer:
I think u missspelled something be cause the the sum would be a good 0.2927
A new rechargeable battery pack is available for products that use aa batteries. Which of the following best explains how the data files in the table can be used to send a targeted e-mail to only those customers who have purchased products that use aa batteries to let them know about the new accessory?.
Answer:
D
Explanation:
Use the products file to generate a list of product IDs that use AA batteries, then use the list of product IDs to search the purchases file to generate a list of customer IDs, then use the list of customer IDs to search the customers file to generate a list of e-mail addresses
is an ocean wave electromagnetic or mechanical
Answer:
mechanical
Explanation:
the energy is carried by water <3 hope this helped
A sailor pulls a boat along a dock using a rope at an angle of 35. 0º with the horizontal. How much work does the sailor do if he exerts a force of 455 N on the rope and pulls the boat 9. 50 m?
Calculate the kinetic energy of a truck that has a mass of 1900 kg and is moving at 45 m/s.
Find the mass of a car that is traveling at a velocity of 75 m/s North. The car has 5,040,000 J of kinetic energy.
How fast is a ball rolling if it contains 108 J of kinetic energy and has a mass of 3. 5 kg?
At an accident science on a level road, investigators measure a car’s skid mark to be 85 m long. The accident occurred on a rainy day, the coefficient of friction was estimated to be 0. 25. What was the speed of the car when the driver slammed on and locked the brakes?
A new conveyor system at the local packaging plan will utilize a motor-powered mechanical arm to exert an average force of 980 N to push large crates a distance of 15 meters in 30 seconds. Determine the power output required of such a motor.
Josh and Jake are both helping to build a brick wall which is 6 meters in height. They each lay 350 bricks, but Josh finishes this task in 2 hours while Jake requires 5. 5 hours to complete his part. Who does more work, or do they both do the same amount? Who has more power? Explain.
please help me
Answer:
What work is done when a person pushes an 80 kg washing machine 12m across the floor. The force of friction between the washing machine and floor is 500 N.
A sailor pulls a boat along a dock using a rope at an angle of 60° with the horizontal. How much work does the sailor do if he exerts a force of 255 N on the rope and pulls the boat 4.0m?
Explanation:
2) What did Rutherford discover in his experiment?
a) nucleus
b) electrons
c) neutrons
Is the equation balanced? Why or why not? 2 Zn + 2 HCl ----------> 2 H2 + 2 ZnCl2 SPS3.bGroup of answer choicesYes because the law of conservation of matter is being followed. The mass of the reactants is equal to the mass of the products.No because the law of conservation of energy is not followed. There are different amounts of energy in the reactants and products.Yes because the law of conservation of energy is followed. There are equal amounts of energy in the reactants and products.No because the law of conservation of mass is not being followed. The hydrogen and chlorine atoms have different numbers of atoms in the reactants and products.
The equation is not balance because the law of conservation of mass is not being followed.
Why the equation is not balanced?The hydrogen and chlorine atoms have different numbers of atoms in the reactants and products which is not balance on both sides i.e. reactant and products.
So we can conclude that the equation is not balance because the law of conservation of mass is not being followed.
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An ideal gas, initially at a volume of 0.777778 L and pressure of 9 kPa, undergoes isothermal expansion until its volume is 7 L and its pressure is 1 kPa. Calculate the work done by the gas during this process. Answer in units of J.
For an ideal gas, initially at a volume of 0.777778 L, the work done by the gas during this process is mathematically given as
w=15.380613
What is the work done by the gas during this process.?Generally, the equation for the work done is mathematically given as
W=p1v1invfvi
Therefore
v2=p1v1/p2
v2=9*1.0.77778/1
v2=7.00002
In conclusion
w=7.00002ln7/0.777778
w=15.380613
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Which describe the image formed by the convex
mirror? Check all that apply.
-real
-virtual
-inverted
-upright
-smaller
-larger
Answer:
virtual, upright, smaller
Explanation:
yes
Objects 1 and 2
attract each other with
a electrostatic force
of 72.0 units. If the charge of Object
is one-third the
original value AND the charge of object 2 is doubled AND
the distance separating Objects 1 and 2 is doubled, then the
new electrostatic force will be
units.
Answer:
12 units
Explanation:
Original F = C q1q2/r^2 now change the parameters
New F = C 1/3 q1 2 q2 / (2r)^2
= 2/12 C q1q2/r^2 <=======the new force is 1/6 of original
1/6 * 72 = 12 units
Yellow light (600 nm) passes
through a diffraction grating. Its first
order (m = 1) maximum occurs at
an angle of 21. 2°. What is the slit
separation d?
[?] x 10-6 m
Hint: Just fill in the number that goes in [?]
Answer:
1.66 x 10^-6 m
Explanation:
A planet's moon travels in an approximately circular orbit of radius 8.6 107 m with a period of 6 h 25 min. Calculate the mass of the planet from this information.
Answer:
m v^2 / R = G M m / R^2 gravitational attraction = centripetal force
M = v^2 R / G solving for M
period = 6 h 25 min = (6 * 3600 + 25 * 60) sec = 23,100 sec = T
v = 2 pi R / T
M = 4 pi^2 R^3 / (G T^2)
M = 39.5 * (8.6E7)^3 / (6.67E-11 * 2.31E4^2)
M = 39.5 * 636 / (6.67 * 5.34) * 10^24
M = 7.05 * 10^26 kg
A planet has a mass 0.051 times the mass of Earth and a diameter of about 0.160 times the diameter of Earth. What is the acceleration of a body falling near the surface of this planet
Answer:
Gravity on planet is 2 times earth gravity
Explanation:
Grav force = G m1 m2 / (r^2) now change m1 and r
= G .051m1 m2 / ( .16 r)^2
= .051 /.0256 G m1 m2 / r^2
.051 /.0256 = ~ 2
A wave has a period of n seconds. What is the frequency of this wave?
Answer:
n Hz
Explanation:
I think I'm Sry if it is wrong.
(02.06 LC)
Etiquette determines which (5 points)
Answer:
Etiquette determines which behaviors are polite and impolite among players and team. It is a code of polite conduct according to social norms and efficiency. Etiquette as a societal rule is formed to enhance positive human relation when interacting and can reduce conflicts in the society. A person who is aware of the etiquette in a given situation will be more confident, comfortable and competent thus making even those around him or her at ease.
In this lab, you will need to be able to describe how multiple waves interact with each other. 1) This does not add too much mathematical complexity to the wave equation (Eq. 2), and 2) it allows us to develop a closer approximation of real-life situations as well (e. G. Interacting ripple patterns in a pond, music, atomic physics, etc. ). Here, you will explore the superposition of two waves, y1 and y2, where:
The superposition of waves due to their interaction can either produce a constructive or destructive interference.
What is wave superposition?Wave superposition refers to the the interaction of two or more waves when their parts overlap.
Example of wave superposition is multiple waves travelling through a rope.
The superposition principle states that when two or more waves overlap in space, the resultant disturbance is equal to the algebraic sum of the individual disturbances.
Based on phase difference between two or more waves, the superposition if the waves can result in either constructive or destructive interference .
Therefore, the superposition of waves due to their interaction can either produce a constructive or destructive interference.
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The Special Olympics started for athletes with which disability?
Answer:
intellectual disabilities
Founded in 1968 by Eunice Kennedy Shriver, Special Olympics provides people with intellectual disabilities continuing opportunities to realize their potential, develop physical fitness, demonstrate courage and experience joy and friendship.
Explanation:
A +1.4 nC charge exerts a repulsive force of 20.0 mN on a second charge
which is located a distance of 2.2 m away from it. What is the magnitude
and sign of the second charge?
Answer:
+ .00769 C
Explanation:
Whoever 'katie' is , removed my previous, innocuous answer for some reason....
The force is repulsive , so the charge is also POSITIVE
f = k q1 q2 / r^2
k = Coulombs constant = 8.98755 x 10^9 kg m^3 . (s^2 C^2)
q 1 = 1.4 x 10^-9 C f = 20 x 10^-3 N
r = 2.2 m q2 = ?
Sub in the values to get q 2 = + .00769 C
A 1,500kg boulder falls off a 120m tall cliff on a planet that has a surface gravitational field of magnitude 3. 6 N/kg. Assume that the planet has no atmosphere. How long does it take for the boulder to strike the ground?
Write your answer using two significant figures
Answer:
8.16 seconds, enjoy physics
A 1,500kg boulder falls off a 120m tall cliff on a planet that has a surface gravitational field of magnitude 3. 6 N/kg. Assume that the planet has no atmosphere, it would take 8.16 seconds for the boulder to strike the ground
What are the three equations of motion?There are three equations of motion given by Newton
The first equation is given as follows
v = u + at
the second equation is given as follows
S = ut + 1/2×a×t²
the third equation is given as follows
v² - u² = 2×a×s
Note that these equations are only valid for a uniform acceleration.
where u and v are the initial and final velocity respectively
S is the total distance covered by the object
a is the acceleration of the object
As given in the problem a 1,500kg boulder falls off a 120m tall cliff on a planet that has a surface gravitational field of magnitude 3. 6 N/kg. Assume that the planet has no atmosphere
S = 120m, the initial velocity of the boulder is zero
u = 0
g = 3.6 m/s²
S = ut + 1/2at²
u= 0m/s , a= 3.6 m/s² and t = ? seconds
120 = 0×t + 0.5×3.6×t²
t² = 120 /(3.6×0.5)
t² = 66.667
t = 8.16 seconds
Thus, it would take 8.16 seconds for the boulder to strike the ground
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How does the amount of solar energy change as Earth orbits the sun
Explanation:
As the Earth orbits the Sun, the tilt causes one hemisphere and then the other to receive more direct sunlight and to have longer days. The total energy received each day at the top of the atmosphere depends on latitude
Answer:
She is right!
Have a good day/Night!
Explanation:
Rex
What happens to the force between charges when: (a) the distance between them is halved?
Answer:
i dont know but ill update you
1. Potential energy and a roller coaster. A 1000-kg roller coaster car moves from point A to B then C.
(a) What is the potential energy at B and C
relative to A?
(b) What is the change in potential energy
as it goes from B to C?
(c) What is the potential energy at B and C relative to point C?
(d) What is the change in potential energy as it goes from B to C?
Answer:(a) With our choice for the zero level for potential energy of the car-Earth system when the car is at point B ,
U
B
=0
When the car is at point A, the potential energy of the car-Earth system is given by
U
A
=mgy
where y is the vertical height above zero level. With 135ft=41.1m, this height is found as:
y=(41.1m)sin40.0
0
=26.4m
Thus,
U
A
=(1000kg)(9.80m/s
2
)(26.4m)=2.59∗10
5
J
The change in potential energy of the car-Earth system as the car moves from A to B is
U
B
−U
A
=0−2.59∗10
5
J=−2.59∗10
5
J
(b) With our choice of the zero configuration for the potential energy of the car-Earth system when the car is at point A, we have U
A
=0. The potential energy of the system when the car is at point B is given by U
B
=mgy, where y is the vertical distance of point B below point A. In part (a), we found the magnitude of this distance to be 26.5m. Because this distance is now below the zero reference level, it is a negative number.
Thus,
343. W/M^2 of energy is emitted by the sun to the earth. How much actually reaches the earth's surface?
A. About one fourth
B. Almost all
C. About a third
D. About half
If 343 W/m² of energy is emitted by the sun to the earth, the quantity that reaches the earth is : ( D ) which is about half.
What is radiation?Radiation is the energy exchange that does not require a material medium for propagation.This is the process in which the sun exchanges heat with the earth.
Analysis:
When heat is exchanged between two bodies, heat is either, absorbed, transmitted or reflected. In the the cloud, energy is reflected back to the sun since the clouds are translucent, it allows a part to reach the clouds.
In conclusion, About half of this energy gets to the earth.
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Answer:
The correct answer is A. About one fourth.planation: