The only force opposing the block's sliding as it slows down is friction with magnitude f . By Newton's second law, the net force in this direction is
∑ F = -f = ma = (4.00 kg) a
Assuming constant acceleration a , the acceleration applied by friction is such that
(1.5 m/s)² - (11 m/s)² = 2a (4.00 m)
Solve for the acceleration :
a = ((1.5 m/s)² - (11 m/s)²) / (8.00 m) ≈ -14.8 m/s²
Then the frictional force exerted a magnitude of
-f = (4.00 kg) (-14.8 m/s²)
f ≈ 59.4 N
and was directed opposite the block's motion.
An electromagnet does not attract a piece of iron.Is it true ? Give reason
Answer:
False..
Explanation:
An electoMagnets attract iron due to the influence of their magnetic field upon the iron. ...
Please help
A man stands on a freely rotating platform with his arms extended, his rotational frequency is 0.25rev/s. But when he draws them in, his frequency is 0.80revs/s. Find the ratio of his moment of inertia in the first case to that in the second.
Answer:
sorry for you
The ratio of the man's moment of inertia in the first case (arms extended) to that in the second case (arms drawn in) is 3.2.
The relationship between the rotational frequency [tex](\(\omega\))[/tex] and moment of inertia (I) is given by the equation:
[tex]\[I_1\omega_1 = I_2\omega_2\][/tex]
where [tex]\(I_1\)[/tex]and [tex]\(I_2\)[/tex] are the moments of inertia in the two cases, and [tex]\(\omega_1\) and \(\omega_2\)[/tex] are the corresponding rotational frequencies.
Let's denote the moment of inertia in the first case (arms extended) as [tex]\(I_1\)[/tex] and in the second case (arms drawn in) as [tex]\(I_2\)[/tex]. The given rotational frequencies are [tex]\(\omega_1 = 0.25 \, \text{rev/s}\) and \(\omega_2 = 0.80 \, \text{rev/s}\)[/tex].
Using the equation [tex]\(I_1\omega_1 = I_2\omega_2\)[/tex], we can rearrange it to solve for the ratio of moments of inertia:
[tex]\[\frac{I_1}{I_2} = \frac{\omega_2}{\omega_1}\][/tex]
Substituting the given values, we have:
[tex]\[\frac{I_1}{I_2} = \frac{0.80 \, \text{rev/s}}{0.25 \, \text{rev/s}}\][/tex]
Simplifying the expression, we get:
[tex]\[\frac{I_1}{I_2} = 3.2\][/tex]
Therefore, the ratio of the man's moment of inertia in the first case (arms extended) to that in the second case (arms drawn in) is 3.2.
know more about inertia:
https://brainly.com/question/3268780
#SPJ2
please help meee please please
Answer:
I think it's c but don't know for sure
1- A soccer ball was kicked from the ground with an initial speed of 12m/s at an
angle 32° above the horizontal. What are the x and y positions of the ball
0.50s after it is kicked?
Answer:
Y = 0.5 × 6.36 m/s = 3.18 meters
X = 0.5 × 10.18 m/s = 5.09 meters
Explanation:
X and Y components:
Y = 6.36 m/s
X = 10.18 m/s
Position after 0.5 seconds:
Y = 0.5 × 6.36 m/s = 3.18 meters
X = 0.5 × 10.18 m/s = 5.09 meters
The x and y positions of the ball 0.50s after it is kicked are 5.09 meter and 1.95 meter respectively.
What is velocity?
The rate at which a body's displacement changes in relation to time is known as its velocity. Velocity is a vector quantity with both magnitude and direction. SI unit of velocity is meter/second.
Given parameters:
Initial speed of the soccer ball at an angle 32° above the horizontal is: u = 12m/s.
Time interval: t = 0.50 second.
Now, x component of initial velocity = u cosθ = 12 × cos 32° m/s = 10.17 m/s.
y component of initial velocity = u sinθ = 12 × sin32° =6.36 m/s.
Hence,
after 0.50 s, x-position of the ball = u cosθ t
= 10.17 × 0.50 meter
= 5.09 meter.
after 0.50 s, y-position of the ball = u sinθ t -gt²/2
= 6.36 × 0.50 - (9.8×0.50²/2) meter
= 1.95 meter.
Learn more about velocity here:
https://brainly.com/question/18084516
#SPJ2
Light from the Sun takes about 8.0 min to reach Earth. How far away is the Sun? Answer in scientific notation
Some amount of ideal gas with internal energy U was heated from 100^0C to 200^0C. We can predict that internal energy after heating in terms of U is:
The internal energy after heating in terms of U is 100U.
The given parameters;
initial temperature of the gas, T₁ = 100 ⁰Cfinal temperature of the gas, T₂ = 200 ⁰CAssuming a constant pressure, the internal energy of the ideal gas is equal to the change in the enthalpy of the ideal gas.
[tex]\Delta H = U \times \Delta T\\\\\Delta H = U (200 - 100)\\\\\Delta H = 100 U[/tex]
Thus, we can conclude that the internal energy after heating in terms of U is 100U.
Learn more here:https://brainly.com/question/15517750
A pumpkin is launched in the air and travels at a horizontal velocity of 25 meters per second for 5 seconds. How far does it travel horizontally?
Answer:
30.3 meters, 172 degrees
Explanation:
To insure the most accurate solution, this problem is best solved using a calculator and trigonometric principles. The first step is to determine the sum of all the horizontal (east-west) displacements and the sum of all the vertical (north-south) displacements.
Horizontal: 2.0 meters, West + 31.0 meters, West + 3.0 meters, East = 30.0 meters, West
Vertical: 12.0 meters, North + 8.0 meters, South = 4.0 meters, North
The series of five displacements is equivalent to two displacements of 30 meters, West and 4 meters, North. The resultant of these two displacements can be found using the Pythagorean theorem (for the magnitude) and the tangent function (for the direction). A non-scaled sketch is useful for visualizing the situation.
Applying the Pythagorean theorem leads to the magnitude of the resultant (R).
R2 = (30.0 m)2 + (4.0 m)2 = 916 m2
R = Sqrt(916 m2)
R = 30.3 meters
The angle theta in the diagram above can be found using the tangent function.
tangent(theta) = opposite/adjacent = (4.0 m) / (30.0 m)
tangent(theta) = 0.1333
theta = invtan(0.1333)
theta = 7.59 degrees
This angle theta is the angle between west and the resultant. Directions of vectors are expressed as the counterclockwise angle of rotation relative to east. So the direction is 7.59 degrees short of 180 degrees. That is, the direction is ~172 degrees.
If a = 8i + j - 2k and b = 5i - 3j + k show that a) a x b = -5i - 18j - 29k b) b X a = 50 + 18j +29k
Recall the definition of the cross product with respect to the unit vectors:
i × i = j × j = k × k = 0
i × j = k
j × k = i
k × i = j
and that the product is anticommutative, so that for any two vectors u and v, we have u × v = - (v × u). (This essentially takes care of part (b).)
Now, given a = 8i + j - 2k and b = 5i - 3j + k, we have
a × b = (8i + j - 2k) × (5i - 3j + k)
a × b = 40 (i × i) + 5 (j × i) - 10 (k × i)
… … … … - 24 (i × j) - 3 (j × j) + 6 (k × j)
… … … … + 8 (i × k) + (j × k) - 2 (k × k)
a × b = - 5 (i × j) - 10 (k × i) - 24 (i × j) - 6 (j × k) - 8 (k × i) + (j × k)
a × b = - 5k - 10j - 24k - 6i - 8j + i
a × b = -5i - 18j - 29k
Answer:
Explanation:
If a = 8i + j - 2k and b = 5i - 3j + k show that a) a x b = -5i - 18j - 29k b) b X a = 50 + 18j +29k
what is the specific latent heat of fusion of water?
Answer:
334
Explanation:
A 30.0-g object moving to the right at 20.5 cm/s overtakes and collides elastically with a 13.0-g object moving in the same direction at 15.0 cm/s. Find the velocity of each object after the collision. (Take the positive direction to be to the right. Indicate the direction with the sign of your answer.)
Let m₁ and m₂ be the masses of the two objects, and v₁ and v₂ their initial velocities. So
m₁ = 30.0 g = 0.0300 kg
m₂ = 13.0 g = 0.0130 kg
v₁ = + 20.5 cm/s = 0.205 m/s
v₂ = + 15.0 cm/s = 0.150 m/s
and we want to find v₁' and v₂', the final velocities of either object after their collision.
Momentum is conserved throughout the objects' collision, so that
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'
where v₁' and v₂' are the first and second object's velocities after the collision.
Kinetic energy is also conserved, so that
1/2 m₁v₁² + 1/2 m₂v₂² = 1/2 m₁(v₁')² + 1/2 m₂(v₂')²
or
m₁v₁² + m₂v₂² = m₁(v₁')² + m₂(v₂')²
From the first equation (omitting units), we have
0.0300 • 0.205 + 0.0130 • 0.150 = 0.0300 v₁' + 0.0130 v₂'
0.0810 = 0.0300 v₁' + 0.0130 v₂'
81 = 30 v₁' + 13 v₂'
From the second equation,
0.0300 • 0.205² + 0.0130 • 0.150² = 0.0300 (v₁')² + 0.0130 (v₂')²
0.00155 ≈ 0.0300 (v₁')² + 0.0130 (v₂')²
1.55 ≈ 30 (v₁')² + 13 (v₂')²
Solving both equations simultaneously gives two solutions, one of which corresponds to the initial conditions. The other yields
v₁' ≈ + 0.172 m/s
and
v₂' ≈ + 0.227 m/s
A patient comes to an outpatient laboratory for a physician-ordered fasting test. The patient indicates that he forgot that the test was to be fasting and ate a candy bar 2 hours ago. The patient insists that you should draw the test because he cannot come back at another time. What should you do?
The patient eating a candy bar instead of fasting for the test should be told
that the test results will be wrong and he may receive a wrong diagnosis.
The medical practitioners told him to fast when coming for a reason and he
forgetting and eating something means the objective for the test may have
been defeated.
This is why it's best to explain to him about the consequences of his actions
which is likely getting a wrong result and diagnosis.
Rad more on https://brainly.com/question/19622125
2- Calculate the momentum of cruise liner of mass 20 000 tones when it is travelling at 6.0ms-1
(1 tonne = 1000kg). Note: tonne
Answer:
P = 120,000,000
Explanation:
P = m.v
m = (20,000.1000)= 20,000,000kg
v = 0.6 m/s
p = (20,000,000)(0.6)
p = 120,000,000 kg⋅m/s
Kinesha and her friend were watching a solar eclipse. Kinesha explains to her friend that a solar eclipse means that Earth is located between the Sun and the Moon. Her friend tells Kinesha that her explanation is incorrect. Why?
this is where the sun and moon line up where you asleep only a tiny bit of the sun it's pretty cool to see
Explanation:
a solar eclipse means when the moon goes infront of the sun and the earth turns dark
A motorcycle moves according to the velocity-time graph
shown in Figure 3.28. Find the average acceleration of
the motorcycle during each of the following segments of
the motion: (a) A, (b) B, and (c) C.
Answer:
a) 1 m/s²
b) -1 m/s²
c) 0 m/s² (constant speed, not accelerating)
Explanation:
A
delta speed = 10 - 0
delta time = 10 - 0
delta speed / delta time = 10/10
delta speed / delta time = 1
B
ds = 5 - 10
dt = 15 - 10
ds / dt = -5 / 5
ds / dt = -1
C
ds = 5 - 5
dt = 25 - 15
ds / dt = 0 / 10
ds / dt = 0
The average acceleration of A, B, and C will be 1 m/s², -1 m/s², and 0 m/s².
What is acceleration?An object is considered to have been accelerated if its velocity changes. Depending on whether an object is moving faster, slower, or in a different direction, its velocity may change. Examples of acceleration include a falling apple, the moon orbiting the earth, and a car that has stopped at a stop sign. These examples demonstrate how acceleration occurs whenever a moving object modifies its direction, speed, or both.
There are different types of acceleration :
Uniform accelerationNon-Uniform AccelerationAverage accelerationAverage acceleration is defined as the average change in velocity with respect to the average change in time.
SI unit is m/s² and it is vector quantity.
According to the question,
For A, Acceleration= (v₁-v₀)/(t₁-t₀)
⇒10-0/10-0
= 1 m/s².
For B, Acceleration= (v₃-v₂)/(t₃-t₂)
⇒5-10/15-10
= -1 m/s²
For C, Acceleration will be constant because change in velocity is constant, this is the case of uniform motion, so its acceleration is also going to be constant (as per the definition of acceleration change in velocity ratio change in time).
For more information about acceleration :
https://brainly.com/question/12550364
#SPJ2
PLEASE HELP DUE TODAY
When same vectors are in the same direction they add. When same vectors are in opposite directions, they
a, also add
b, subtract
c, multiply
d, divide
Answer:
The answer is a (also add)
electric field due to on the surface of the charge sphere
Explanation:
static electricity draws energy
The octopus’s tentacle keeps _ right after it is bitten off ? a. Moving b. Breathing c. Growing
Answer:
The answer is A
Explanation:
The octopus’s tentacle keeps moving right after it is bitten off
How much force is required to raise a 0.2 kg mass?
Answer:
1.96 N
Explanation:
⇒This is your full answer
A country is deciding what to do about pollution glven off by power plants.
Which of the following is an example of how science can be used to make
this decision?
O A. Scientists own most of the power plants in the United States.
O B. Scientists can measure how much pollution is given off
O C. Scientists know what kind of power plants people want.
OD. Scientists are allowed to pass laws about pollution
Answer:
option B is the correct answer
Explanation:
please follow me and Mark me brainliest please
As a bicycle pump inflates a tyre, it pressure rises from 30 kPa to 40 kPa at constant temperature of 30 °C. By assuming the air acts as an ideal gas, calculate the work done per mol of the air.
A. -80.35 J
B. 80.35 J
C. -811.93 J
D. 811.93 J
(please show calculation)
can use this formula W=nRT ln(p1/p2)
Answer:
B.-80.35 J
i dont know the calculation
An electron is held up against the force of gravity by the attraction of a fixed proton some distance above it. How far above the electron is the proton
5.08 m
Explanation:
The weight of the electron is being counteracted by the attractive electrostatic force exerted by the proton above it. We can write the force equation as follows:
[tex]m_eg = k_e\dfrac{Q_pQ_e}{r^2}[/tex]
where the Q's are the charges of the proton and electron, r is the distance between the particles, g is the acceleration due to gravity, [tex]m_e[/tex] is the mass of the electrons and [tex]k_e[/tex] is the Coulomb constant. So solving for r, we get
[tex]r^2 = k_e\dfrac{Q_pQ_e}{m_eg}[/tex]
Taking the square root of r^2, we then get the distance as
[tex]r = \sqrt{k_e\dfrac{Q_pQ_e}{m_eg}}[/tex]
The values are given as follows:
[tex]m_e = 9.11×10^{-31}\:\text{kg}[/tex]
[tex]g = 9.8\:\text{m/s}^2[/tex]
[tex]Q_p = Q_e = 1.60×10^{-19}\:\text{C}[/tex]
[tex]k_e = 8.99×10^9\:\text{N-m}^2\text{/C}^2[/tex]
Putting in all of these values in our equation for r,
[tex]r = \sqrt{\dfrac{(8.99×10^9\:\text{N-m}^2\text{/C}^2)(1.60×10^{-19}\:\text{C})^2}{(9.11×10^{-31}\:\text{kg})(9.8\:\text{m/s}^2)}}[/tex]
[tex]\:\:\:\:\:= 5.08\:\text{m}[/tex]
name two examples where the cohesive force dominates over the adhesive force and vice versa
Cohesive forces are the forces that draw molecules of the same type together. Adhesive forces are those that draw molecules of various types together.
What is the difference between cohesive force and adhesive force?Cohesive forces are the forces that draw molecules of the same type together. Adhesive forces are those that draw molecules of various types together.
The force that draws molecules of the same substance together is called the cohesive force. The force that holds molecules of various substances together is known as the adhesive force.
Between molecules of the same substance, there are cohesive forces. There is a natural tendency to resist separation due to these intermolecular forces between like elements. Conversely, adhesive forces draw disparate molecules together.
In physics, cohesion refers to the intermolecular attraction that exists between two adjacent parts of a substance, especially one that is solid or liquid. A piece of matter is held together by this force. Adhesion is a term for the intermolecular forces that act when two dissimilar substances come into contact.
To learn more about cohesive and adhesive force refer to:
https://brainly.com/question/18041818
#SPJ2
A child at the top of a slide de has a gravitational store of 1800J. What is the child's maximum kinetic store as he slides down? Explain why
Hi there!
We know that:
Initial Total Mechanical Energy = Final Total Mechanical Energy
(Ei = Ef)
In this instance:
Ei = Gravitational Potential Energy
Ef = Kinetic Energy
In the absence of friction, ALL of the initial potential energy will be changed into kinetic energy at the bottom of the slide. Thus, the maximum kinetic energy of the child will be 1800 J.
(a) What frequency is received by a person watching an oncoming ambulance moving at 105 km/h and emitting a steady 853 Hz sound from its siren
Answer:
(a) f' = 878 Hz
(b) f' = 735 Hz
Explanation:
What's the kinetic energy of an object that has a mass of 12 kilograms and moves with a velocity of 10 m/s?
Answer:
600 JExplanation:
Given,
Mass (m) = 12 kgVelocity (v) = 10 m/sAs we know,
Kinetic Energy,
[tex] E_{k} \: = \frac{1}{2} m {v}^{2} [/tex]Therefore ,
Kinetic energy of the object is,
[tex] = \frac{1}{2} \times 12 \: kg \times 10 \: m {s}^{ - 1} \times 10 \: m {s}^{ - 1} [/tex]
(On dividing 12 by 2 we get 6)= (6 × 10 × 10) J [As 'J' stands for 'joule']
= 600 J (Ans)
Sam wants to get a refrigerator into a moving truck. He chooses to use a ramp to accomplish the task that is 25 meters long. If the fridge weighs 250 N, what force will Sam need to use on the ramp to get the fridge into the 3 m high truck bed?
Answer:
Explanation:
Ignoring friction and assuming one ramp end rests on level ground.
gravity acceleration acting parallel to the ramp is gsinθ.
F = mgsinθ
mg = 250 N, sinθ = 3/25
F = 250(3/25)
F = 30 N
A 25 meter long ramp strong enough to hold a person plus a 250 N refrigerator would weigh much more than 250 N.
the temperature of ice will rise until melting state select true or false
Answer:
True
Explanation:
I have learned that in grade schoolI have known that for quite awhile now alsoWork is required to lift a barbell. How many times more work is required to lift the barbell 2 times as high?
Answer:
2 times more work
Explanation:
Work is a force times distance
W = Fd
The barbell does not change mass so its weight (force) is constant.
That means work is directly proportional to the distance traveled.
twice the distance means twice the work.
Is the acceleration change or constnt?
Four year old Sam has been hitting other children at preschool. He may have learned this behavior from his parents who regularly spank him. What approach to personality best explains Sam's behavior?
A. psychodynamic
B. behavioral
C. humanistic
D. biological
A. psychodynamic is the personality best explains Sam's behavior
What is psychodynamic ?
The psychology of mental or emotional forces or processes developing especially in early childhood and their effects on behavior and mental states is called psychodynamic .
Since , any behavior is not genetical or it never get inherited hence it is not biological . This has been grown with time and this behavior have been grown in Sam by observing his parents doing the same hence correct option should be A. psychodynamic
learn more about psychodynamic
https://brainly.com/question/10373312?referrer=searchResults
#SPJ2