Answer:
? có thể cụ thể hơn ko
Explanation:
A force of 50 N stretches a string by 4 cm,calculate the elastic constant.
Answer:
50/0.04= answer
A bullet of mass m, moving horizontally with speed u, meets a block of wood of mass M, travelling along the same line but in the opposite direction with speed ,U, and remains embedded in it. Show that the loss of kinetic energy is of the form 1/2kMm, where k is in terms of u, U, m, M and find the loss in KE when the bullet of mass 4.0g, travelling at 890ms^-1 hits a block of wood, mass 4.0kg moving at 7.0ms^-1
Answer:
Explanation:
First of all we shall calculate the velocity of composite mass . Let it be v . Applying law of conservation of momentum
mu - MU = ( m + M ) v
v = mu - MU / ( m + M )
loss of kinetic energy
= 1/ 2 mu² + 1/2 MU² - 1/2 ( M +m ) v²
= 1/ 2 mu² + 1/2 MU² - 1/2 ( M +m ) (mu - MU)² / ( m + M )²
= 1/ 2 mu² + 1/2 MU² - 1/2 (mu - MU)² / ( m + M )
= 1/2 [ m²u² + mMu² +mMU² + m²U² - m²u² - M²U² - 2 muMU ] / ( m + M )
= 1 / 2 [ mMu² + mMU² - 2 muMU ] / ( m + M )
= 1 / 2mM [ (u² + U² - 2 uU) / ( m + M )]
= 1/2 mM x k
where
k = [ (u² + U² - 2 uU) / ( m + M )]
Given
m = .004 kg
M = 4 kg
u = 890 ms⁻¹
U = 7 ms⁻¹
k = ( 890² + 7² - 2 x 890 x 7 ) / 4.004
= ( 792100 + 49 - 12460 ) / 4.004
= 194727.52
loss of kinetic energy
= 1/2 mM x k
= .5 x .004 x 4 x 194727.52
= 1557.82 J .
Question 14 of 30
A bundle of roofing shingles slides off a roof and is falling to the ground. As it
falls, what kind of energy does it possess?
O A. Kinetic only
O B. Potential only
O C. Radiant
D. Kinetic and potential
Answer:
kinetic and potential
Consider a block on a spring oscillating on a frictionless surface. The amplitude of the oscillation is 11 cm, and the speed of the block as it passes through the equilibrium position is 62 cm/s. What is the angular frequency of the block's motion
Answer:
The angular frequency of the block is ω = 5.64 rad/s
Explanation:
The speed of the block v = rω where r = amplitude of the oscillation and ω = angular frequency of the oscillation.
Now ω = v/r since v = speed of the block = 62 cm/s and r = the amplitude of the oscillation = 11 cm.
The angular frequency of the oscillation ω is
ω = v/r
ω = 62 cm/s ÷ 11 cm
ω = 5.64 rad/s
So, the angular frequency of the block is ω = 5.64 rad/s
A cell membrane has a thickness of about 7 nm. How many cell membranes would it take to make a stack 2.3 in high?
Answer:
There are 8345714 cell membranes.
Explanation:
It is given that,
The thickness of a cell membrane is 7 nm
We need to find the number of cell membranes would it take to make a stack 2.3 inches high.
Firstly, the units must be same i.e. converting 2.3 inches to m
1 inch = 0.0254 m
2.3 inches = 0.05842 m
Let there are n number of cell membranes. So,
[tex]n=\dfrac{\text{stack height}}{\text{1 membrane thickness}}\\\\n=\dfrac{0.05842}{7\times 10^{-9}}\\\\n=8345714.28[/tex]
or
n = 8345714 cell membranes
direct or indirect
"Susan is a lovely ten-year-old girl from Hawaii."
Answer:
Direct
Explanation:
A speed that will permit a train or other equipment to stop within one half the range of vision short of a train, engine, railroad car, man or equipment fouling a track, stop signal or a derail or switch lined improperly. When a train or engine is required to move at restricted speed, the crew must keep a lookout for a broken rail and not exceed 20 mph:__________
Answer:
This is called restricted speed
Why does it take a longer time for a kilogram of water than a kilogram of copper to reach the same temperature?
Answer:
Since water has a higher specific heat than copper.
Explanation:
Dimensionally speaking, the specific heat of a material ([tex]c[/tex]) is represented by:
[tex][c] = \frac{[Energy]}{[Mass]\cdot [Temperature]}[/tex]
The specific heats of water and copper are [tex]4186\,\frac{J}{kg\cdot ^{\circ}C}[/tex] and [tex]390\,\frac{J}{kg\cdot ^{\circ}C}[/tex], respectively. Let suppose that temperature change and masses of water and copper are the same. Then, a kilogram of water takes a longer time than a kilogram of copper since the first has a higher specific heat.
can anyone help me to explain theory of relativity???
Answer:
The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of gravitation and its relation to other forces of nature.It applies to the cosmological and astrophysical realm, including astronomy.
The theory transformed theoretical physics and astronomy during the 20th century, superseding a 200-year-old theory of mechanics created primarily by Isaac Newton. It introduced concepts including spacetime as a unified entity of space and time, relativity of simultaneity, kinematic and gravitational time dilation, and length contraction. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves
Saul is testing an installation and discovers a short circuit what’s causing this
A.high current
B.high voltage
C.low resistance
D.low voltage
Answer:
im pretty sure that it's (A.) High current
Explanation:
pf
not 100% sure, tho
think about the objects which acts as concave or convex Mirrors in your surroundings write a report on it
Answer:
Explanation:
S.No Concave Mirror Convex Mirror
1. Dentist's mirror Rear view mirror of vehicles
2. Shaving Mirror Streetlights
3. Headlight of vehicles Water glass surface
4. Caving side of spoon Curving side of spoon
5. Torch glass Electric Bulb
6. Inner surface of Outer surface of steel basin
steel basin
7. Lunch plates Calling bell
8. Microscope Optical instruments
9. Satellite dishes Fish eye lenses
When is the net force on an object equal to zero? A. When the object is in motion B. When the object is changing direction C. When the forces acting on the object are balanced D. When inertia is not present pls i need the answers quick
Answer: C. when the forces acting on the object are balanced.
Answer:
c
Explanation:
claculate the pressure exerted by the water on the bottom of a deep dam of 12m from its surface .(density of water =1000kg/m sqare)
Explanation:
We know that,
[tex]hydrostatic \: pressure (p) = \alpha hg [/tex]
Where,
[tex] \alpha = density \: of \: water \: = 1000[/tex]
h = Height at which pressure is to be calculated
[tex]p = 1000 \times 12 \times 9.8 = 117600 \: [/tex]
si t=2h ¿cuál es el valor de N? PORFAVOR AYUDA
Answer:
I don't know ur Language????
Eli and Andy want to find out which of the two is stronger. Eli pushes a table with a force of 120 newtons while Andy pushes the table from the opposite side with a force of 125 newtons. Ignoring the masses of Eli and Andy, what is the resultant acceleration of the table if its mass is 10.0 kilograms?
Answer:
a = 0.5 m/s²
Explanation:
the type of problem is called a Newtons second law of motion.
and the equation would be the sum of F = m * a where m = mass and a = acceleration
forces are 125N and the opposite direction is 120N
Eli pushes the table with a force of 120N towards Andy
and
Andy pushes the table with a force of 125N towards Eli
mass of table given as 10 kg.
using the equation
120N - 125N = 10kg * a
a = (120-125) / 10
a = -0.5 m/s² so the acceleration is in the direction of Andy's force towards Eli.
therefore a = 0.5 m/s²
Answer:
B.
0.50 meters/second2
Explanation:
5. Which one of the following factors is directly proportional to density of liquid? (a) Temperature (b) Volume of liquid (c) Upthrust (d) Density of object
Answer:
A
The upthrust on a floating body is in upwards direction and is equal to the weight of the liquid displaced
B
The upthrust is directly proportional to the density of the liquid in which the solid is immersed
C
The upthrust is directly proportional to the volume of the fluid displaced by a solid
The upthrust acts on the body in upward direction at the center of buoyancy.
Upthrust is equal to the weight of liquid displaced by object and weight of liquid will depend on its density.
Upthrust is F=Vρg ,where V is the volume of liquid displaced and ρ is the density of fluid.
The total lateral pressure acting on an immersed object on one side is equal and in opposite direction to the total lateral pressure acting on the other side.
Millimeters, centimeters, meters,
kilometers, inches, feet, and
miles are all examples of
plz help
Millimeters, centimeters, meters, kilometers, inches, feet, and miles are all examples of unit of length like: distance between two points and displacement of any object.
What is unit?The quantity with a constant magnitude that is used to measure the magnitudes of other quantities of the same type is referred to as a unit in physics.The formula: physical quantity = numerical value × unit. can be used to determine a physical quantity's magnitude.A unit shouldn't alter as time or environmental factors like pressure and temperature change.It ought to be precisely defined.It need to be readily available and repeatable.Meter is a Si unit of length whereas centimeter is CGS unit of length and Feet is FPS unit of lengths. Another units are also useful in measuring lengths.
Learn more about units here:
https://brainly.com/question/12750330
#SPJ2
Two mass m1 and m2 lie on a frictionless surface. Between the two masses is a compressed spring, with spring constant k. The system is held in place. At time t=0 the blocks are released. The blocks move off in opposite directions with velocities v1 and v2. how much was the spring compressed?
Answer:
The spring was compressed the following amount:
[tex]\Delta x=\sqrt{ \frac{m_1\,v_1^2+ m_2\,v_2^2}{k} }[/tex]
Explanation:
Use conservation of energy between initial and final state, considering that the surface id frictionless, and there is no loss in thermal energy due to friction. the total initial energy is the potential energy of the compressed spring (by an amount [tex]\Delta x[/tex]), and the total final energy is the addition of the kinetic energies of both masses:
[tex]E_i=\frac{1}{2} k\,(\Delta x)^2\\\\E_f=\frac{1}{2} m_1\,v_1^2+\frac{1}{2} m_2\,v_2^2[/tex]
[tex]E_i=E_f\\[/tex]
[tex]\frac{1}{2} k\,(\Delta x)^2=\frac{1}{2} m_1\,v_1^2+\frac{1}{2} m_2\,v_2^2\\k\,(\Delta x)^2=m_1\,v_1^2+ m_2\,v_2^2\\(\Delta x)^2=\frac{m_1\,v_1^2+ m_2\,v_2^2}{k} \\\Delta x=\sqrt{ \frac{m_1\,v_1^2+ m_2\,v_2^2}{k} }[/tex]
is a corroding metal a physical or chemical change?
Answer:
Coording metal is a physical change.
A 970-kg sports car collides into the rear end of a 2300-kg SUV stopped at a red light. The bumpers lock, the brakes are locked, and the two cars skid forward 2.9 m before stopping. The police officer, estimating the coefficient of kinetic friction between tires and road to be 0.80, calculates the speed of the sports car at impact.
Answer:
22.73 m/s or 81.72 kph
Explanation
We can find the combined mass of both cars as
970 kg + 2300 kg = 3270 kg.
Then the normal force of the cars can be calculated as
F(n)= mg
Where g is acceleration due to gravity 9.8m/s^2
3270 kg ×9.8 = 32046 kg*m/s^2.
coefficient of kinetic friction between tires and road to be 0.80 × F(n)
Then the frictional force can be calculated as
= (32046kg*m/s^2 × 0.80 )
= 25636.8 kg*m/s^2
We can now calculate the work done that was used stopping the cars as
Frictional force × distance
(25636.8 kg*m/s^2 ) × 2.9m= 74346.72kg*m^2/s^2
From kinetic energy formula, the combined velocity of the car can be determined
E=0.5 M V²
√(2E/M) = V
√(2*74346.72kg*m^2/s^2 / 3270 kg) = V
V= √ (45.472)
V=6.743293m/s
the momentum of both cars can be determined as
6.743293m/s * 3270 kg
= 22050.57kg*m/s
Now the final momentum of both cars must be equal to the the momentum of
the sports car just prior to the collision. Therefore, the speed of the sports car at impact.
=(22050.57 kg*m/s) / 970 kg = 22.73 m/s
We can convert that to km/h.
22.73 m/s * 3600 s/h / 1000 m/km = 81.72 kph
Trên một đoạn đường thẳng AC cho điểm B nằm giữa AC sao cho BC = 4AB . Tại thời điểm t = 0 xe thứ nhất chuyển động đều qua A với tốc độ v1 hướng về C, xe thứ hai chuyển động đều qua B với tốc độ v2 cùng hướng với xe thứ nhất. Đến thời điểm t = 1.5h hai xe gặp nhau tại C. Biết rằng quảng đường mỗi xe đi dược trong một giờ hơn kém nhau 10km. Tính v1, v2 và khoảng cách từ A đến C.
Answer:
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URGENT!! Look at attached image to see question.
Explanation:
The answer is option B
The number of reactant molecules and product molecules is even.
Question 1 (2 points)
(01.01 LC)
Which of the following is a characteristic of science? (2 points)
QU
Reproducible by other scientists
Ob
The personal opinion of the scientist
С
Using variable conditions for each test
d
Including only the data that supports a hypothesis
Answer:
Reproducible by other scientists
Explanation:
I just took the test
If the boy on the bicycle in the preceding problem accelerates from rest to a speed of 10.0 m/s in 10.0 s, the angular acceleration of the tires is:_______
Answer:
The angular acceleration is 3.33 rad/s²
Explanation:
Here is the preceding problem as well as the given problem:
A boy rides his bicycle 2.00 km. The wheels have radius 30.0 cm. What is the total angle the tires rotate through during his trip?
21.
If the boy on the bicycle in the preceding problem accelerates from rest to a speed of 10.0 m/s in 10.0 s, what is the angular acceleration of the tires?
Explanation:
To determine the angular acceleration, we will first find the linear accelerationFrom one of the equations of kinematics for linear motion
v = u + at
Where v is the final speed
u is the initial speed
a is the linear acceleration
and t is time
From the question, the boy starts from rest, hence,
u = 0.0 m/s
v = 10.0 m/s
t = 10.0 s
a = ??
From, v = u + at
a = [tex]\frac{ v - u}{t}[/tex]
a = [tex]\frac{10 - 0}{10}[/tex]
a = 1 m/s²
Now, for the angular acceleration, [tex]\alpha[/tex]
The relationship between linear acceleration, a and angular acceleration, [tex]\alpha[/tex] is
a = [tex]\alpha[/tex]r
where r is radius
From the previous question, r = 30.0cm = 0.3m
From the equation, a = [tex]\alpha[/tex]r
[tex]\alpha[/tex] = a / r
[tex]\alpha[/tex] = 1 / 0.3
[tex]\alpha[/tex] = 3.33 rad/s²
Which of the following will cause an induced current in a coil of wire? A. A wire carrying a constant current near the coil B. A magnet being moved into or out of the coil C. The constant field of the Earth passing through the stationary coil D. A magnet stationary resting near the coil
Answer:
B. A magnet being moved into or out of the coil
Explanation:
Faraday law of electromagnetic induction states that when there is change in flux , an emf is produced . Among the given instances , only in case of B , flux is changing . So current will be induced in the coil . We shall see how it takes place .
A wire carrying constant current will produce magnetic flux in nearby coil but there is no change in flux because current as well as position of wire with respect to coil are not changing .
Passing of magnetic field through a stationary coil produces flux in the coil but here too there is no change in flux so no current will be induced .
A magnet positioned near a coil creates magnetic flux in the coil but the magnitude of flux remains constant so no change in flux and no creation of induced current .
An action force is 75 N up. The reaction force must be:
!ASAP!
The reaction force must be:
75 N up
A greater applied force is required to move an object with a greater mass than one with a smaller mass.
True
False
Answer:
True
Explanation:
The bigger an object is, the more force you must apply to move the object. Think about it like moving a mouse compared to moving an elephant. You can't move the elephant by yourself, because you don't have enough strength or force to move it. But, you can easily pick up a mouse, because it requires less force, or strength. Hope this helped :)
Answer:
I don't know
Explanation:
sorry but I will help u next time kk
the indiscriminate use of drugs without the doctor's prescription is called
Answer:
drug misuse
Explanation:
this is because the person is using those drugs but indiscriminately meaning without correct judgement or in this context without a prescription therefore without following guidelines and legal standards eg self medication
but it is not abuse because it is being used for its intended purpose just without any guidelines
Value of g increases with the
(a) increase in mass of the body
(b) increase in altitude
(c) decrease in altitude
(d) none of the above
Answer:
increase in mass of body
. Mass of a man is 40 kg. find his weight (g=9.8 m/s?)
Answer: 392N
Explanation: W=mg
W= 40x9.8
= 392N
Answer:
[tex]\large \boxed{\sf 392.4 \ N}[/tex]
Explanation:
[tex]\sf Weight \ (N) =mass \ (kg) \times acceleration \ of \ gravity \ (m/s^2)[/tex]
[tex]W=mg[/tex]
[tex]W=40 \times 9.81[/tex]
[tex]W= 392.4[/tex]