Answer:
256 N
Explanation:
formula of centripetal force = mv²/r
m= 2kg
v= 8m/s
r= 0.5m
mv²/r = 2×8²/0.5 = 256N
A runner having mass of 55 kg moving at a speed of 9 m/s rounds a bend with a radius of 18 m. What is the centripetal
Answer:
247.5 N
Explanation:
From the question,
The expression of centriputal force is given as
F = mv²/r..................... Equation 1
Where m = mass of the runner, v = velocity of the runner, r = radius of the runner
Given: m = 55 kg, v = 9 m/s, r = 18 m
Substitute these values into equation 1
F = 55(9²)/18
F = 247.5 N.
Hence the centriputal force of the runner is
247.5 N
help me plz!!!!!!. what difference between center of gravity and center of mass
Answer:
I think that the centre of mass is the point at which the distribution of mass is equal in all directions, and does not depend on gravitational field. Centre of gravity is the point at which the distribution of weight is equal in all directions, and does depend on gravitational field
The knee extensors insert on the tibia at an angle of 30 degrees (from the longitudinal axis of the tibia), at a distance of 3 cm from the axis of rotation at the knee. How much force must the knee extensors exert to produce an angular acceleration at the knee of 1 rad/s2 , given a mass of the lower leg and foot of 4.5 kg, and a radius of gyration of 23 cm
Answer:
the knee extensors must exert 15.87 N
Explanation:
Given the data in the question;
mass m = 4.5 kg
radius of gyration k = 23 cm = 0.23 m
angle ∅ = 30°
∝ = 1 rad/s²
distance of 3 cm from the axis of rotation at the knee r = 3 cm = 0.03 m
using the expression;
ζ = I∝
ζ = mk²∝
we substitute
ζ = 4.5 × (0.23)² × 1
ζ = 0.23805 N-m
so
from; ζ = rFsin∅
F = ζ / rsin∅
we substitute
F = 0.23805 / (0.03 × sin( 30 ° )
F = 0.23805 / (0.03 × 0.5)
F F = 0.23805 / 0.015
F = 15.87 N
Therefore, the knee extensors must exert 15.87 N
what is amplitudes relationship between sound and amplitudes
Answer:
A sound wave's amplitude relates to changes in pressure. The sound is perceived as louder if the amplitude increases, and softer if the amplitude decreases. This is illustrated below. DOSITS short video on amplitude.
If the mass of a moving object is doubled, which variable will also double? *
(7 points)
momentum
final velocity
acceleration
potential energy
Answer:
potential energy
Explanation:
this is because potential energy= mgh
so when m= 2m
p.e. = 2 times the previous value
Therefore , When mass is doubled , Potential energy gets doubled. When mass is halved , Potential energy decreases by half.
A force of 12 N changes the momentum of a toy car from 3kgm/s t0 10kgm/s. Calculate the time the force took to produce this change in momentum.
Answer:
Time = 0.58 seconds
Explanation:
Given the following data;
Initial momentum = 3 kgm/s
Final momentum = 10 kgm/s
Force = 12 N
To find the time required for the change in momentum;
First of all, we would determine the change in momentum.
[tex] Change \; in \; momentum = final \; momentum - initial \; momentum [/tex]
[tex] Change \; in \; momentum = 10 - 3 [/tex]
Change in momentum = 7 kgm/s
Now, we can find the time required;
Note: the impulse of an object is equal to the change in momentum experienced by the object.
Mathematically, impulse (change in momentum) is given by the formula;
[tex] Impulse = force * time [/tex]
Making "time" the subject of formula, we have;
[tex] Time = \frac {impulse}{force} [/tex]
Substituting into the formula, we have;
[tex] Time = \frac {7}{12} [/tex]
Time = 0.58 seconds
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One of the greatest dangers in a tornado is from flying objects. A 15 pound piece of lumber can turn into a flying missile that could severely damage walls and homes. A piece of steel with a mass of 200 pounds and travelling at the same velocity would cause even more damage. Select any evidence from the list below that you could use to explain why a 200 pound piece of steel would cause more damage than a 15 pound piece of wood travelling at the same velocity.
As the kinetic energy of an object increases, the force it can exert on another object decreases.
As the kinetic energy of an object increases, the force it can exert on another object increases.
Objects with more mass have less kinetic energy.
Objects with more mass have more kinetic energy.
As the velocity of an object increases, its kinetic energy decreases.
As the velocity of an object increases, its kinetic energy increases.
I uploaded the answer to a file hosting. Here's link:
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You exert a 138 N push the leftmost of two identical blocks of mass 244 g connected by a spring of stiffness 605 kg/s2. After pushing the block a distance 15 cm, you release it; by this time the rightmost block has moved a distance 5 cm. (a) What is the energy in the oscillations between the blocks
Answer:
the energy in the oscillations between the blocks is 3.025 J
Explanation:
Given the data in the question;
Force f = 138 N
stiffness of spring k = 605 kg/s²
mass of block = 202 g = 0.202 kg
pushing the block a distance 15 cm, the rightmost block has moved a distance 5 cm
i.e
x₁ = 15 cm
x₂ = 5cm
the energy in the oscillations between the blocks will be;
E[tex]_A[/tex] = E[tex]_B[/tex] = [tex]\frac{1}{2}[/tex]k( Δx )²
we substitute
= [tex]\frac{1}{2}[/tex] × k( 15 - 5 )² × 10⁻⁴
= [tex]\frac{1}{2}[/tex] × 605 × ( 10 )² × 10⁻⁴
= [tex]\frac{1}{2}[/tex] × 605 × 100 × 10⁻⁴
= 3.025 J
Therefore, the energy in the oscillations between the blocks is 3.025 J
On a cold winter day, a steel metal fence post feels colder than a wooden fence post of identical size because: a. The specific heat capacity of steel is higher than the specific heat capacity of wood. b. The specific heat capacity of steel is lower than the specific heat capacity of wood. c. Steel has the ability to resist a temperature change better than wood. d. The mass of steel is less than wood so it loses heat faster. Selected:e. Two of the above statements are true.
Answer:
The specific heat capacity of steel is lower than the specific heat capacity of wood
Explanation:
THERE IS ONLY 1 ON MY assignment i geot dis right please brainlyist
The specific heat capacity of steel is lower than the specific heat of a piece of wood. Therefore, option (2) is correct.
What is the specific heat capacity?Specific heat can be defined as the heat energy required to change the temperature of one unit mass of a substance of a constant volume by 1 °C. The S.I. unit of the specific heat capacity of a material is KJ/Kg.
The thermal capacity of a material is defined as a physical property of a substance. The amount of heat is given to a given mass to create a change in unit temperature.
The mathematical expression of specific heat capacity can be written as :
Q = m C ΔT Where C is the heat capacity.
The specific heat capacity is an intensive property of a substance as it does not depend upon the size of the material.
A steel metal fence post feels colder than a wooden fence post of similar size because the specific heat of steel is lower than the specific heat capacity of wood.
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g Two long parallel wires are a center-to-center distance of 2.50 cm apart and carry equal anti-parallel currents of 2.70 A. Find the magnitude of the magnetic field at the point P which is equidistant from the wires. (R
Answer:
864 mT
Explanation:
The magnetic field due to a long straight wire B = μ₀i/2πR where μ₀ = permeability of free space = 4π × 10⁻⁷ H/m, i = current in wire, and R = distance from center of wire to point of magnetic field.
The magnitude of magnetic field due to the first wire carrying current i = 2.70 A at distance R which is mid-point between the wires is B = μ₀i/2πR.
Since the other wire also carries the same current at distance R, the magnitude of the magnetic field is B = μ₀i/2πR.
The resultant magnetic field at B is B' = B + B = 2B = 2(μ₀i/2πR) = μ₀i/πR
Now R = 2.50 cm/2 = 1.25 cm = 1.25 × 10⁻² m and i = 2.70 A.
Substituting these into B' = μ₀i/πR, we have
B' = 4π × 10⁻⁷ H/m × 2.70 A/π(1.25 × 10⁻² m)
B = 10.8/1.25 × 10⁻⁵ T
B = 8.64 × 10⁻⁵ T
B = 864 × 10⁻³ T
B = 864 mT
This question involves the concept of the magnetic field due to two current-carrying wires in the same direction, parallel to each other.
The magnitude of the magnetic field at the point P, which is equidistant from the wires is "8.64 x 10⁻⁵ T".
The following formula is used to find the magnetic field at the center distance between two parallel current-carrying wires in the same direction:
[tex]B = \frac{\mu_oI_1}{2\pi r}+\frac{\mu_oI_2}{2\pi r}\\\\But,\ I_1=I_2=I\\\\B = \frac{\mu_oI}{\pi r}[/tex]
where,
B = magnetic field at required point = ?
μ₀ = permeability of free space = 4π x 10⁻⁷ H/m
I = current = 2.7 A
r = distance from wires to the point = 2.5 cm/2 = 1.25 cm = 0.0125 m
Therefore,
[tex]B=\frac{(4\pi\ x\ 10^{-7}\ H/m)(2.7\ A)}{\pi (0.0125\ m)}[/tex]
B = 8.64 x 10⁻⁵ T
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(1) Which appliance is designed to transfer electrical energy to kinetic energy?
D)
A food mbuer
BB kettle
Clamp
D radio
Answer:
bb kettle
Explanation:
it transfres electricsl to kinetic
Which of these is the BEST answer for why science is important?
Science can take us to other planets, even if it’s only through a telescope.
Science is part of human nature; it helps answer questions about how the world works.
Science helps us learn to think more critically and weigh evidence better.
Science gives us better tablet computers and games.
QQQUUUUCCCKKKK!!!!!!
Assume your computer has a power rating of 50.0 W, and you use your computer for 7.0 hours a day for a normal school day. If the electric company charges $0.10 per kWh, how much does it cost you to use your computer each school day?
35$
$0.035
$0.005
$0.35
A string is wound tightly around a wheel. When the end of the string is pulled through a distance of 10 cm, the wheel rotates through 5 revolutions. What is the radius of the wheel
Answer:
0.318cm
Explanation:
The computation of the radius of the wheel is shown below:
As we know that
One revolution of the wheel = 2πr
Here r denotes the radius of the wheel
Now
5 revolutions of the wheel would be
= 2πr × 5
= 10πr
So,
10πr = 10cm
Thus r = 1 ÷ π
= 0.318cm
The radius of the wheel will be r=0.318 cm
What will be the radius of the wheel?The radius is defined as the distance between the center of circle and the outer layer of the circle.
It is given in the question that
Revolutions of the wheel = 5
The length of the string =10 cm
Now the radius will be calculated as
One revolution of the wheel
= [tex]2\pi r[/tex]
Now 5 revolutions of the wheel would be
= [tex]2\pi r\times 5=10\pi\ r[/tex]
Since the string has the length of 10 cm then
[tex]10\pi\ r=10[/tex]
[tex]r=\dfrac{10}{10\pi}[/tex]
[tex]r=0.318\ cm[/tex]
Thus the radius of the wheel will be r=0.318 cm
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Which of the following changes when an unbalanced force acts on an object?
A. mass
B. motion
C. inertia
D. weight
The answer is Motion
Kevin decides to soup up his car by replacing the car's wheels with ones that have 1.4 times the diameter of the original wheels. Note that the speedometer in a car is calibrated based on the tire's diameter and on the distance the tire covers in each revolution. (a) Will the reading of the speedometer change
Answer:
No.
Explanation:
Given that Kevin decides to soup up his car by replacing the car's wheels with ones that have 1.4 times the diameter of the original wheels. Note that the speedometer in a car is calibrated based on the tire's diameter and on the distance the tire covers in each revolution. (a) Will the reading of the speedometer change ?
Considering the formula
V = wr
Where
V = linear speed
W = angular speed
r = radius of the wheel.
But W = 2πrf
Where the the 2 and pi are constant. The radius of the first wheel will be small but counter balance with the larger frequency.
While the radius of the second wheel may be large but it will be of a small frequency.
We can therefore conclude that the reading on the speedometer will not change. Because speedometer will read the linear speed V.
A cylindrical body has 6 m height and its radius is 2 metre calculate its volume. Ans :75.428m3
Answer:
75.4
Explanation:
r= 2
h= 6
v= 22/7 *r*r*h
v= 75.42
please answer asap!! thank you for the help, will mark brainliest if correct!
The color of visible light depends on the wavelength of the light.
Please select the best answer from the choices provided
T
F
Answer:
Its true
Explanation:
but im answering so the other person can get brainliest :3
To everyone who sees this, have a wonderful day or night!
why food cook faster with salt water than cook with pure water
Answer:
oil heats faster
Explanation:
If you blow across the open end of a soda bottle and produce a tone of 250 Hz, what will be the frequency of the next harmonic heard if you blow much harder?
___Hz
Answer:
Generally, the lowest overtone for a pipe open at one end and closed would be at y / 4 where y represents lambda, the wavelength.
Since F (frequency) = c / y Speed/wavelength
F2 / F1 = y1 / y2 because c is the same in both cases
F2 = y1/y2 * F1
F2 = 3 F1 = 750 /sec
Note that L = y1 / 4 = 3 y2 / 4 for these wavelengths to fit in the pipe
and y1 = 3 y2
The second harmonic will be three times the first harmonic. The answer is 750 Hz
VIBRATION OF WAVES IN PIPESClosed pipes have odd multiples of frequencies or harmonics. That is,
If [tex]F_{0}[/tex] = fundamental frequency = first harmonic
[tex]F_{1}[/tex] = 3[tex]F_{0}[/tex] = second harmonic
[tex]F_{2}[/tex] = 5[tex]F_{0}[/tex] = third harmonic
[tex]F_{3}[/tex] = 7[tex]F_{0}[/tex] = fourth harmonic
Let assume that the first harmonic is 250 Hz, If you blow it much harder, second, third or fourth harmonic can be produced.
By using the formula above,
second harmonic will be 3 x 250 = 750Hz
Therefore, the frequency of the next harmonic heard if you blow much harder will be 750 Hz
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PLEASE HELP The United States spends over $20 billion a year on space exploration through NASA. Do you think that this has been worth the cost? In three to five sentences, provide two specific examples of things we have learned from space exploration, and explain how these examples influence your opinion.(4 points)
Answer: I think $20 billion a year it’s worth the cost. The reasoning behind that is because we can conduct research on various things that could help out humanity. Therefore we can conclude that’s spending billions of dollars every year is worth it.
Explanation:
Please help I need help I can’t fail .
Answer:
A
Explanation:
Gas particles move fastest.
Plasma lacks fixed volume and shape.
Liquid lacks fixed shape, but has fixed volume.
Solid has both fixed volume and shape.
Calculate the force that would be required to enact 50 joules of work on an object that was displaced by 2 meters.
Answer:
Force = 25 N
Explanation:
Given:
Work done = 50 J
Displacement = 2 m
Find:
Force
Computation:
Work done = Force x displacement
50 = Force x 2
Force = 25 N
It requires 3480 J to move a 675 N object how far?
Diffraction occurs for all types of waves, including sound waves.
a. True
b. False
Answer:
a. True
Explanation:
Sound are mechanical waves that are highly dependent on matter for their propagation and transmission.
Sound travels faster through solids than it does through either liquids or gases. A student could verify this statement by measuring the time required for sound to travel a set distance through a solid, a liquid, and a gas.
Mathematically, the speed of a sound is given by the formula:
[tex] Speed = wavelength * frequency [/tex]
Generally, the frequency of a sound wave determines the pitch of the sound that would be heard.
Diffraction occurs for all types of waves, including sound waves.
A red pool ball is rolling directly east before it collides with the
white cue ball moving directly north. Due to conservation of
momentum the total momentum of both objects after the
collision would be in which direction?
Answer: North East
Explanation: Trust me, I was just doing this on the Ck-12 and this the answer I choose and It said I'm correct.
Do blood cells have a nuclei? Describe the shape of blood platelets.
Answer: Mature red blood cells don't have nuclei.
Explanation: " Platelets are irregularly shaped, have no nucleus, and typically measure only 2–3 micrometers in diameter. "
Hope this Helps!!
Carl works hard to get a grades on his report card because his mother pays him 25 dollars for each semester he earns straight as Carl’s behavior is being influenced by
A car with a mass of 1200 kg has a momentum of 15, 350 kg * m/s. What is its velocity?
Answer:
v = 12.79 m/s
Explanation:
Given that,
The mass of a car, m = 1200 kg
Momentum of the car, p = 15 350 kg-m/s
We need to find the velocity of the car. We know that, the formula for the momentum of an object is given by :
p = mv
Where
v is the velocity of the bject
So,
[tex]v=\dfrac{p}{m}\\\\v=\dfrac{15350}{1200}\\\\v=12.79\ m/s[/tex]
So, the velocity of the car is 12.79 m/s.
1 A roller coaster starts from rest at A, rolls down the track to B, describes a circular loop of 12-m diameter, and travels up and down past point E. Determine the range of values of h for which the roller coaster will not leave the track at D or E. Assume no energy loss due to friction.
Answer:
15m
Explanation:
Given that a roller coaster starts from rest at A, rolls down the track to B, describes a circular loop of 12-m diameter, and travels up and down past point E. Determine the range of values of h for which the roller coaster will not leave the track at D or E. Assume no energy loss due to friction
Solution
At point A
The maximum potential energy = maximum K.E
At point A, the total energy = maximum P.E.
Down the track to point B, the P.E will be converted to maximum K.E.
Hence,
Mgh = 1/2mv^2
Also, the total energy at the roller coaster will be P.E + K.E
I.e mg2r + 1/2mv^2
Where 2r = height of the loop = diameter of the loop.
Since the energy is always conserved, hence
Mgh = mg2r + 1/2mv^2
Let also consider the centripetal acceleration to keep the object in the circle.
F = mV^2 / r = mg
Mass will cancel out
U^2 = rg
Substitute that in the last equation
Mgh = mg2r + 1/2mgr
mgh = mg ( 2r + 1/2r )
Mg will cancel out
h = 2.5r
Where r = 12/2 = 6
h = 2.5 × 6
h = 15m
Therefore, the values of h for which the roller coaster will not leave the track at D or E is 15m.