Answer:
A 20 Hz sound wave is 75 m long in the water (1500/20 = 75) whereas a 20 Hz sound wave in air is only 17 m long (340/20 = 17) in air. As we descend below the surface of the sea, the speed of sound decreases with decreasing temperature.
5
A cyclist travels 125 km in 5 hours. How fast is the cyclist moving?
Answer:
25 km/h
Explanation:
speed=distance÷time
125÷5=speed
125÷5=25 (then add units)
A wheel of mass 50 kg has a radius of 0.4 m. It is making 480 rpm. What is the
torque necessary to bring it to rest in 40 seconds?
Solution:
Answer:
The torque necessary to bring the wheel to rest in 40 seconds is 10.4 N·m
Explanation:
The question is with regards to rotational motion
The rotary motion parameters are;
The mass of the wheel = 50 kg
The radius of the wheel = 0.4 m
The rate of rotation of the wheel = 480 rpm
The time in which the wheel is to be brought to rest = 40 s
The rotational rate of the wheel in rotation per second is given as follows;
480 r.p.m = 480 r.p.m × 1 minute/(60 seconds) = 8 revolution/second
1 revolution = 2·π radians
Therefore, we have the angular velocity, ω, given as follows;
ω = 2·π × 8 revolutions/second ≈ 50.3 rad/s
The angular acceleration, α, is given as follows;
[tex]\alpha = \dfrac{\Delta \omega}{\Delta t} = \dfrac{\omega _2 - \omega_1}{t_2 - t_1}[/tex]
Whereby the wheel is brought to rest from its initially constant rotational motion in 40 seconds, we have;
ω₁ ≈ 50.3 rad/s, ω₂ = 0 rad/s, and t₂ - t₁ = 40 seconds
Plugging in the values for the variables of the equation for the angular acceleration, "α", we get;
[tex]\alpha = \dfrac{0 - 50.3 \ rad/s}{40 \ s} \approx 1.3 \ rad/s^2[/tex]
The torque on the wheel, τ, is given as follows;
τ = m·r²·α
Where;
m = The mass of the object = 50 kg
r = The radius of the wheel = 0.4 m
α = The acceleration of the wheel ≈ 1.3 rad/s²
Therefore;
τ = 50 kg × (0.4 m)² × 1.3 rad/s² ≈ 10.4 N·m
The torque necessary to bring the wheel to rest in 40 seconds = τ ≈ 10.4 N·m.
Answer:
-10.048 N m
Explanation:
Look at the atoms below
a. Atom W: 9 protons and 9 neutrons
b. Atom X: 8 protons and 9 neutrons
c. Atom Y: 9 protons and 9 neutrons
d. Atom Z: 9 protons and 10 neutrons
Which ones below are isotopes of each other and why?
element z are isotopes because number of netron are different and number of protons are same
What is the gravitational force of attraction between a 55 kg boy and a 40 kg girl if they are 0.10 meters apart?
Answer:
[tex]1.5\cdot 10^{-5}\:\mathrm{N}[/tex]
Explanation:
Newton's Law of Gravitation is given as:
[tex]F=G\frac{m_1m_2}{r^2}[/tex], where [tex]G[/tex] is gravitational constant [tex]6.67\cdot 10^{-11}[/tex] and [tex]r[/tex] is the distance between their centers of mass.
Therefore, the gravitational force between them is:
[tex]F=6.67\cdot 10^{-11}\frac{55\cdot40}{0.1^2}= \fbox{$1.5\cdot 10^{-5}\:\mathrm{N}$}[/tex] (two significant figures).
320 joules of work were done by a force of 80 newtons. Over what
distance was the force applied?
44m
80m
4m
40m
Answer:
[tex]4\:\mathrm{m}[/tex]
Explanation:
The formula for work is given as [tex]W=F\Delta x[/tex] where [tex]F[/tex] is force applied and [tex]\Delta x[/tex] is displacement.
Rearranging this equation, we have:
[tex]\Delta x=\frac{W}{F}[/tex].
Plugging in given values, we get:
[tex]\Delta x=\frac{W}{F}=\frac{320}{80}=\fbox{$4\:\mathrm{m}$}[/tex].
Answer:
The answer is 4m
Explanation:
hope this helps!
find not true when the water freezes...
Answer: i think its c
Explanation:
Answer:
a
Explanation:
HELP ME ASAP PLZZ
Which of the following is not a measurement taken by a radiosonde?
a. atmospheric composition
b. atmospheric pressure
c. wind speed
d. wind direction
Answer:
A atmospheric composition
if a 2kg ball has and initial velocity of
4 m/s and is kicked and accelerated to
10 m/s in one second, what is the force that was applied to the ball? Rember that acceleration is the change in velocity/ change in time
please help me asap
Answer:
[tex]\boxed {\boxed {\sf 12 \ Newtons }}[/tex]
Explanation:
Force is equal to the product of mass and acceleration.
[tex]F=m*a[/tex]
We know the mass, but not the acceleration. Therefore, we must calculate it before we can calculate force.
1. Calculate Acceleration
Acceleration is the change in velocity over the change in time.
[tex]a=\frac{V_f-V_i}{t}[/tex]
The final velocity is 10 meters per second and the initial velocity is 4 meters per second. The time is 1 second.
[tex]V_f=10 \ m/s \\V_i= 4 \ m/s \\t= 1 \ s[/tex]
Substitute the values into the formula.
[tex]a=\frac{10 \ m/s-4 \ m/s }{1 \ s}[/tex]
Solve the numerator.
[tex]a=\frac{6 \ m/s}{1 \ s }[/tex]
Divide.
[tex]a= 6 \ m/s/s=6 \ m/s^2[/tex]
2. Calculate Force
Now we know the acceleration and the mass.
[tex]m= 2 \ kg \\a= 6 \ m/s^2[/tex]
Substitute the values into the fore formula.
[tex]F= 2 \ kg * 6 \ m/s^2[/tex]
Multiply.
[tex]F= 12 \ kg*m/s^2[/tex]
1 kilogram meter per square second is equal to 1 Newton. Our answer of 12 kg*m/s² is equal to 12 Newtons[tex]F= 12 \ N[/tex]
The force applies to the ball was 12 Newtons.
How much of the matter in the universe is comprised
of atoms?
a. 1%
b. 100%
c. 30%
d. 99%
Answer: I believe the correct answer is A.
Absorption of a light wave occurs in what material?
Answer: I think Windows.
Explanation: The absorption of light makes an object dark or opaque to the wavelengths or colors of the incoming wave: Wood is opaque to visible light. Some materials are opaque to some wavelengths of light, but transparent to others. Glass and water are opaque to ultraviolet light, but transparent to visible light.
Option.D-All materials is the correct answer.
Any object, whether living or inert, has the ability to absorb light. Absorption is always influenced by the electromagnetic frequency of the light being transmitted (i.e., its color) and the composition of the object's atoms.
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Which image illustrates the bouncing of a light wave off of a surface?
A
B
с
D
A. A
B. B
C. C
Answer:
The answer is A good luck :P
Answer:
A
Explanation:
The light Bounces off because it is reflecting off glass or anything else
Help !!!!!!!!
Please its Urgent.
None can.
A clinical thermometer only measures temperatures above +30°C.
Mercury and alcohol are both frozen solid at -50°C.
A squirrel runs at a speed of 9.9 m, with 25 J of kinetic energy. What is the squirrel’s mass?
Answer:
The mass of the squirrel is 0.51kg
A squirrel runs at a speed of 9.9 m/s with 25 J of kinetic energy.
What is the squirrel’s mass?
Answer: 0.51 kg
A cart falls from a track with an acceleration of 10 m/s2 (which is always the acceleration due to gravity). If it falls for 9 seconds before hitting the ground, what is it’s velocity at impact? (show work plz)
Answer:
90m/s
Explanation:
Given parameters:
Acceleration = 10m/s²
Time of fall = 9s
Unknown:
Final velocity = ?
Solution:
We can assume that the cart falls from rest.
Initial velocity = 0m/s
Using
v = u + gt
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
t is the time
v = 0 + 10 x 9 = 90m/s
Answer:
90m/s
Explanation:
someone please help with this
Answer:
The new force is 2/3 of the original force
Explanation:
Coulomb's Law
The electrical force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between the two objects.
Written as a formula:
[tex]\displaystyle F=k\frac{q_1q_2}{d^2}[/tex]
Where:
[tex]k=9\cdot 10^9\ N.m^2/c^2[/tex]
q1, q2 = the objects' charge
d= The distance between the objects
Suppose the first charge is doubled (2q1) and the second charge is one-third of the original charge (q2/3). Now the force is:
[tex]\displaystyle F'=k\frac{2q_1*q_2/3}{d^2}[/tex]
Factoring out 2/3:
[tex]\displaystyle F'=\frac{2}{3}k\frac{q_1*q_2}{d^2}[/tex]
Substituting the original force:
[tex]F'=\frac{2}{3}F[/tex]
The new force is 2/3 of the original force
(a) Explain the advantage of using a plane mirror in optical testing.
explain your answer
Answer: Optical test is a test which is used to assess vision and ability of the person to focus on the objects.
Explanation:
The following are the advantages of utilizing plane mirror in optical testing:
1. When a plane mirror is used for testing the image of the test card must be placed at distance equal to the distance of the object.
2. Larger distance in between the object or test card and viewer is obtained. This can help in determining the exact ability of the eye to focus on objects.
How many centimeters are there in 9.3 meters
Answer:
930 centimeters
Explanation:
A 5.0 kg chunk of putty moving at 10m/s collides and sticks to a 7.0 kg bowling ball that is initially at rest.What is the total momentum of the bowling ball and the putty after they collide?
Answer:
Total momentum = 50kgm/s
Explanation:
Given the following data;
Mass, M1 = 5kg
Mass, M2 = 7kg
Velocity, V1 = 10m/s
Velocity, V2 = 0m/s (since it's at rest).
To find the total momentum;
Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.
Mathematically, momentum is given by the formula;
[tex] Momentum = Mass * Velocity [/tex]
The law of conservation of momentum states that the total linear momentum of any closed system would always remain constant with respect to time.
Total momentum = M1V1 + M2V2
Substituting into the equation, we have;
Total momentum = 5*10 + 7*0
Total momentum = 50 + 0
Total momentum = 50 kgm/s
Therefore, the total momentum of the bowling ball and the putty after they collide is 50 kgm/s.
A piece of glass weights 25 g in air, 16.77g in water at 4C and 16.89g in water at 60C. Find the mean coefficient of cubical expansion of water between 4C anf 60C, taking the coefficient of linear expansion of glass as 8*10^6
sorry i think so i dont exactly know i am sorry
Explanation:
As a certain amount of water is cooled from room temperature until it reaches 4 °C, its volume drops. The density reduces as the volume increases below 4 °C. Therefore, water's greatest density occurs at 4 degrees Celsius.
What coefficient of cubical expansion of water?Water has an unusual trait called anomalous expansion, which causes it to enlarge rather than compress when the temperature drops from 4 °C to 0 °C, and it becomes less dense.
At temperatures not far below zero degrees Celsius, water ice is unique for having low coefficients of static and dynamic friction that range from 0.04-0.02, but as the temperature drops, these numbers rise.
Therefore, When a metal sheet's temperature rises by one degree, its coefficient of area expansion is calculated as the increase in surface area per unit of original surface area.
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ANSWER QUICK 30 POINTS
What force controls the movement of the planets around the sun, holds together stars grouped in galaxies, and galaxies grouped in clusters? Thoroughly explain your answer, making sure to include an example and describe how this force keeps planets in orbit. Make sure to write at least 3-5 sentences and proper conventions (spelling, grammar, punctuation, etc.) to respond. Put all answers in your own words (pls dont just take my points :( )
Answer:
Gravity creates stars and planets by pulling together the material from which they are made.
Explanation: Thats the only thing i have im stuck on the tga quiz
The diagram shows a wave traveling through a medium.
Identify point B.
amplitude
crest
trough
wavelength
The point B represent the crest of the wave. The crest is the peak of the wave. While the trough is the lowest.
What is wavelength?The distance between two successive troughs or crests is known as the wavelength.
The wavelength is also defined as the distance between two locations in a wave that have the same oscillation phase.
The point B represent the crest of the wave. The crest is the peak of the wave. While the trough is the lowest.
Hence, option B is correct.
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Compounds are made from the atoms of two or more______?
Answer:
elements
not really an explanation
a cellphone weighing 80 g is flying to the air at 15 m/s what is it's kinetic energy
Answer:
9J
Explanation:
Given parameters:
Mass of cell phone = 80g
1000g = 1kg
80g is therefore 0.08kg
Velocity of the cellphone = 15m/s
Unknown:
Kinetic energy of the cellphone = ?
Solution:
The kinetic energy of a body is the energy due to its motion.
It is expressed as:
K.E = [tex]\frac{1}{2}[/tex] mv² = [tex]\frac{1}{2}[/tex] x 0.08 x 15² = 9J
I need the answers ASAP.
Answer:
Explanation:
A) Large: As she opens her parachute, she begins to displace a large volume of air. This leads to a Large air resistance
B) increase, weight: As she falls, the air resistance force increases. Now there is a force acting in opposite directions to her weight.
C)Weight, Decelerate: The skydiver has only the downward force of her weight pulling down on her, so she starts to decelerate
D) Weight, Upward, Resultant:
Her weight is now equal to the upward force from the ground. Her resultant force is then zero
E) Increases, same, constant, resultant, terminal:
As she accelerates faster, the air resistance force increases. It is now the same as her weight. She now moves at a constant speed because the resultant force acting on her is zero. She is now at her terminal velocity.
F) Increases, same, constant, terminal:
As she decelerates, the air resistance force on her parachute increases until it is the same as her weight. She is now moving with a constant speed until she hits the ground - a new slower terminal velocity
aluminum has a density of 270 kg/m3. what volume of aluminum would have a mass of 49.9 kg?
(unit = m^3)
0.184[tex]m^{3}[/tex] is the answer for Acellus students!
A ____ shows all of the forces acting on an object.
Answer:
Free body diagram
Explanation:
A free body diagram shows all the forces acting on a body. Since force is a vector quantity, the magnitude and direction of the forces are shown in the free-body diagram.
Force is the push or pull on a body.
It can be via contact or without contact. Such non-contact forces acts via a force field.
In physics, this free body diagram is used extensively.
From what Tim explains in the movie, what can you infer about the temperature inside a refrigerator?
Answer:
It's closest to 3 degrees celsius
Explanation:
Please help i don't get it.
Which image matches the Topographic Map Shown?
Also, please explain how your answer is the correct answer. Why is your answer correct?
Answer:
the answer is 4
Explanation:
the picture matches eachother that's why I picked 4
Answer:
devils tower
Explanation:
on the topographic map the circular lines stop at at certain point because the moutain doesnt get any pointyer if you know what that means
in other words if the map continued with the circular lines all the way to the centerit would have been that snowny mountain
a) Las siglas M. RU significan
Answer:
Ver la explicación a continuación.
Explanation:
En física estas siglas significan movimiento rectilíneo uniforme, es decir es el tipo de movimiento donde la velocidad es constante. La velocidad no cambia con el tiempo.
Este tipo de movimiento se puede describir con la siguiente ecuación.
[tex]x=x_{0}+v*t[/tex]
Donde:
x = posición final [m]
xo = posición inicial [m]
v = velocidad [m/s]
t = tiempo [s]
A dog playing fetch starts at rest and accelerates at 4.5m/s2 north. It takes the dog 7 seconds to catch the ball. What was the speed of the dog when he caught the ball?
Answer:
31.5m/s
Explanation:
Given the following
acceleration a = 4.5m/s²
Time t= 7secs
Required
Final speed v = ?
Using the equation of motion
v = u+at
v = 0+4.5(7)
v = 31.5m/s
Hence the speed of the dog is 31.5m/s