Answer:
μ = tan θ
Explanation:
For this exercise let's use the translational equilibrium condition.
Let's set a datum with the x axis parallel to the plane and the y axis perpendicular to the plane.
Let's break down the weight of the block
sin θ = Wₓ / W
cos θ = W_y / W
Wₓ = W sin θ
W_y = W cos θ
The acrobat is vertically so his weight decomposition is
sin θ = = wₐₓ / wₐ
cos θ = wₐ_y / wₐ
wₐₓ = wₐ sin θ
wₐ_y = wₐ cos θ
let's write the equilibrium equations
Y axis
N- W_y - wₐ_y = 0
N = W cos θ + wₐ cos θ
X axis
Wₓ + wₐ_x - fr = 0
fr = W sin θ + wₐ sin θ
the friction force has the formula
fr = μ N
fr = μ (W cos θ + wₐ cos θ)
we substitute
μ (Mg cos θ + mg cos θ) = Mgsin θ + mg sin θ
μ = [tex]\frac{(M +m) \ sin \ \theta }{(M +m) \ cos \ \theta }[/tex]
μ = tan θ
this is the minimum value of the coefficient of static friction for which the system is in equilibrium.
Friction forces cannot change the speed and direction of an object True or false
Answer:
false
Explanation:
This statement is false since frictional force always reduces the speed of and object and also always acts opposite to the direction of a motion. The correct answer is False
FRICTION
Frictional force is a force that opposes motion of an object.
When an object is in motion, the speed of the object will be constant only when the forces acting on the object are balanced. That is, the frictional force balanced or equal to the force applied. A balanced force cannot change the speed and direction of an object in motion.
There will be change in speed and direction when forces acting on the object are not balanced.
Friction forces cannot change the speed and direction of an object. This statement is false since frictional force always reduces the speed of and object and also always acts opposite to the direction of a motion.
Therefore, the correct answer is False.
Learn more about Friction here: https://brainly.com/question/1424758
A ball is attached to one end of a wire, the other end being fastened to the ceiling. The wire is held horizontal, and the ball is released from rest. It swings downward and strikes a block initially at rest on a horizontal frictionless surface. Air resistance is negligible, and the collision is elastic. The masses of the ball and block are, respectively, 1.48 kg and 2.77 kg, and the length of the wire is 1.11 m. Find the velocity of the ball just after the collision.
Answer: Velocity of the ball just after the collision is -1.414 m/s.
Explanation:
As energy is conserved in a reaction so here, energy before collision will be equal to the energy after collision.
[tex]E_{before} = mgh = E_{after} = \frac{1}{2}mv_{o}^{2}[/tex]
where,
m = mass
g = gravitational energy = [tex]9.8 m/s^{2}[/tex]
h = height or length
[tex]v_{o}[/tex] = initial velocity
Also here, height is the length of wire. Let the height be denoted by 'L'. Therefore,
[tex]\frac{1}{2}mv_{o}^{2} = mgL\\v_{o}^{2} = 2gL\\v_{o} = \sqrt{2gL}\\= \sqrt{2 \times 9.8 m/s^{2} \times 1.11 m}\\= 4.66 m/s[/tex]
Formula used to calculate velocity after the collision is as follows.
[tex]v_{f ball} = v_{o} [\frac{m_{ball} - m_{block}}{m_{ball} + m_{block}}][/tex]
where,
[tex]v_{f ball}[/tex] = final velocity of ball after collision
[tex]m_{ball}[/tex] = masses of ball
[tex]m_{block}[/tex] = masses of block
Substitute the values into above formula as follows.
[tex]v_{f ball} = v_{o} [\frac{m_{ball} - m_{block}}{m_{ball} + m_{block}}]\\= 4.66 m/s [\frac{1.48 kg - 2.77 kg}{1.48 kg + 2.77 kg}]\\= 4.66 m/s \times (-0.303)\\= -1.414 m/s[/tex]
Thus, we can conclude that velocity of the ball just after the collision is -1.414 m/s.
A device known as an optical resonator is used in lasers. An optical resonator consists of an arrangement of mirrors that reflect electromagnetic radiation back and forth within an empty cavity. The electromagnetic radiation within the cavity reflects off of the mirrors multiple times. The mirrors are precisely placed so that only particular frequencies can survive within the cavity via constructive interference. All other frequencies are suppressed via destructive interference. The end result is a beam of light of a certain frequency.
An optical resonator of the type described above depends on the tendency of light to
A. behave as a wave.
B. excite atoms to certain energy levels.
C. excite electrons to certain energy levels.
D. behave as a particle.
Answer:
A. The resonator behaves as a wave guide (a hollow pipe used as a transmission line). The characteristics of the pipe depend on the type of the wave to be transmitted.
Examine the model of the phrases of the moon. Which of these statements is true, based on the information shown in the model.
Select ALL that apply.
A) The new moon occurs when the moon is the sun.
B) The quarter moons occur when the moon is closest to the sun
C) The Full moons Occur when the moon is farthest from the earth.
D) The relative position of the moon, Earth, Sun causes the moon phases.
E) Only half of the moon is illuminated by the sun at any point in the cycle
Answer:
D and E
Explanation:
I had this quiz as well so-
03: A mass with a 60 g vibrate at the end of a spring. The amplitude of the motion is 0.394 ft
and a frequency is 0.59 HZ. Find the perind and spring constant, the maximum speed and
acceleration of the mass, the speed and acceleration when the displacement is 6 cm, compute the
kinetic and the potential energy when the position is 6 cm
Answer:
a) T = 1.69 s, b) k = 0.825 N / m, c) v = 1.46 feet/s, d) a = 5.41 ft / s²,
e) v = - 1,319 ft / s, a = - 2.70 ft / s², f) K = 4.8 10⁻³ J, U = 1.49 10⁻³ J
Explanation:
In a mass-spring system with simple harmonic motion, the angular velocity is
w = [tex]\sqrt{\frac{k}{m} }[/tex]
a) find the period
angular velocity, frequency, and period are related
w = 2π f = 2π / T
f = 1 / T
T = 1 / f
T = 1 / 0.59
T = 1.69 s
b) the spring constant
w = 2π f
w = 2π 0.59
w = 3.70 rad / s
w² = k / m
k = w² m
k = 3.70² 0.060
k = 0.825 N / m
c) the maximum speed
simple harmonic movement is described by the expression
x = A cos (wt + Ф)
speed is defined by
v =[tex]\frac{dx}{dt}[/tex]
v = -A w sin (wt + fi)
the speed is maximum when the cosine is ± 1
v = A w
v = 0.394 3.70
v = 1.46 feet/s
d) maximum acceleration
a = [tex]\frac{dv}{dt}[/tex]
a = - A w² cos wt + fi
the acceleration is maximum when the cosine is ±1
a = A w²
a = 0.394 3.70²
a = 5.41 ft / s²
e) velocity and acceleration for x = 6 cm
let's reduce the cm to feet
x = 6 cm (1 foot / 30.48 cm) = 0.1969 foot
Before doing this part we must find the phase angle (Ф), the most common way to start the movement is to move the spring a small distance and release it, so its initial speed is zero for t = 0 s
let's use the expression for the velocity
v = -A w sin (0 + Фi)
0 = - A w sin Ф
so sin Ф = 0 which implies that Фi = 0
the equation of motion is
x = A cos wt
x = 0.394 cos 3.70t
we substitute
0.1969 = 0.394 cos 370t
3.70 t = cos⁻¹ (0.1969 / 0.394)
let's not forget that the angle is in radians
3.70, t = 1.047
t = 1.047 / 3.70
t = 0.2826 s
we substitute this time in the equation for velocity and acceleration
v = - Aw sin wt
v = - 0.394 3.70 sin 3.70 0.2826
v = - 1,319 ft / s
a = - A w² cos wt
a = - 0.394 3.70² cos 3.70 0.2826
a = - 2.70 ft / s²
f) the kinetic and potential energy at this point
K = ½ m v²
let's slow down to the SI system
v = 1.319 ft / s (1 m / 3.28 ft) = 0.402 m / s
K = ½ 0.060 0.402²
K = 4.8 10⁻³ J
U = ½ k x²
U = ½ 0.825 0.06²
U = 1.49 10⁻³ J
What are the two forces acting on a balanced hot air balloon.
of
O a. Gravity and Weight
O b.
Air resistance and upthrust
O c. Applied force and upthrust
d.
Gravity and air resistance
Answer:
I want to say option C) Applied force and upthrust.
Explanation:
Sorry if my answer is wrong. You can look in your book or study up on the website.
⦁ An electron is moving through a 10 T magnetic field at a speed of 3.5 x107m/s perpendicular to the direction of the field. What is the force that applied on the charge?
Answer:
F = 5.6 10⁻¹¹ N
Explanation:
The magnetic force is given by
F = q v x B
The bold indicate vectors, the scalar form of this expression is
F = q v B sin θ
in this case they indicate that the speed and the magnetic field are perpendicular, so the angle is 90º and the sin 90 = 1
F = q v B
the magnitude of the force is
F = 1.6 10⁻¹⁹ 3.5 10⁷ 10
F = 5.6 10⁻¹¹ N
If objects are traveling in opposite directions, what do you know about the signs of their momenta?
Explanation:
the impulse and momentum change on each object are equal in magnitude and opposite in directions. Thus the total momentum is reserved
They have no overall momentum at all. They are travelling in opposing directions yet having the same mass and velocity. Their momentum vectors add up to exactly zero when added together.
What If objects are travelling in opposite directions?When two objects collide, opposite-direction forces of equal magnitude are exerted to each item. When there are such pressures, it usually happens that one item speeds up and gains momentum, while the other object slows down (lose momentum).
Think about a situation where two similar objects are going in opposite directions at the same speed. It's noteworthy to note that despite both items moving, the momentum of the system as a whole is zero because the oppositely oriented vectors cancel out.
Therefore, Every object experiences an equal but opposite change in impulse and momentum. Thus, the entire momentum is held back.
Learn more about objects here:
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whem completing an emergency Roaside stop,it is necessary to put on your parking brake
A. True
B. False
Answer:
trueeeeeeee..........mmmm...........
If acceleration is zero what statement about velocity is true *
A)Velocity is zero
B)Velocity is constant
C)Velocity cannot be determined
D) Velocity is changing
Answer:
Option"B" is correct.
Explanation:
when a body move with constant velocity then acceleration is zero.
If the acceleration of an object is 0, it means the velocity of an object is constant and not changing with respect to time,
So, the correct option will be :
=》B)Velocity is constant
What is a negative effect of increased carbon dioxide within the carbon cycle?
Answer:
Explanation:
Carbon dioxide controls the amount of water vapor in the atmosphere and thus the size of the greenhouse effect. Rising carbon dioxide concentrations are already causing the planet to heat up.
Planet X has a moon similar to Earth’s moon.
Which path would this moon’s orbit take?
PLZ help 10 points!!! space question!
Answer:
B. They are smaller and made of rocky material
Explanation:
i think it's right??
Consider the model of the energy transformation of this system. What can you say about N and M in the model?
A) M < N
B) N = M
C) N < M
D) N + M =
Model of the energy transformation of this system we can say about N and M in the model is M < N.
What is energy?Energy is the ability or capability to do tasks, such as the ability to move an item (of a certain mass) by exerting force. Energy can exist in many different forms, including electrical, mechanical, chemical, thermal, or nuclear, and it can change its form.
The model shows the energy transformation in electrical appliance Fan the is lass of energy in form of heat so M < N.
Model of the energy transformation of this system we can say about N and M in the model is M < N.
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A sled on ice moves in the way described . Friction is so small that it can be ignored. A person wearing spiked shoes standing on the ice can apply a force to the sled and push it along the ice. Choose the one force (A through G) which would keep the sled moving as described. Which force would keep the sled moving toward the right and speeding up at a steady rate (constant acceleration)
The question is not complete, so i have attached an image of the complete question and the image of the sled on the ice.
Answer:
A) 3
B) 7
C) 5
D) 5
E) 5
Explanation:
A) Looking at the image attached, The force that will continue to move the sled toward the right and speeding up at a steady rate would have to be a force acting towards the right and has constant strength (magnitude).
Thus, option 3 is correct.
B) The force that will continue to move the sled toward the right and at Constant velocity will be when no force is applied because at constant velocity, acceleration is zero and thus force will also be zero.
Thus, option 7 is correct.
C) The force that will slow the sled when moving to the right at steady rate(constant acceleration) would be an opposite force which means a force towards the left with a constant strength (magnitude).
Thus, option 5 is correct.
D) The force exerted on the sled by a person when the sled is accelerating to the right would be the normal force exerted on the person by the ice).
Thus, option 5 is correct.
E) The reaction to the normal force exerted on the sled by the ice when the sled is accelerating to the left would be the normal force exerted by the sled on the ice
Thus, option 5 is correct
Please help...
!!!!!!!
Answer:
1) C. The precise location of weather-related phenomena
2) C. It shows that the galaxies are moving farther away.
Explanation:
1) The global positioning system can be used in many ways, like in navigation, mapping and surveying the land. It is also used to observe the small changes taking place in the movement of objects on earth. They are usually used to study earthquakes.
2) When light from the galaxies is shifted towards the longer wavelengths, it is called red shift. When light shifts towards the shorter wavelengths, it is called blue shift. Big bang theory states how the primordial universe started expanding from a hot and dense singularity, in the process of evolution of the universe.
The universe is expanding always. Galaxies that are a part of the universe keep expanding and move farther away from each other. The galaxies that are very far off appear to move much faster than the nearby galaxies.
People, animals, and all matter on Earth are
A. drawn toward the center of Earth by the planet's gravity
B. drawn toward other matter on Earth like the trees and the buildings, since all matter has gravity
C. not affected by Earth's gravity because people are so small in
comparison to the planet
D. held to Earth's surface by their own gravity
Answer:
A
Explanation:
To answer this, we can use process of elimination.
B: This question states that all matter has gravity. This is not correct. All matter is *effected* by gravity, but we do not have gravity inside of us.
C: If this were the case, we would all be floating off into space.
D: Same issue as question B.
Two long, straight wires are separated by a distance of 32.2 cm. One wire carries a current of 2.75 A, the other carries a current of 4.33 A. (a) Find the force per meter exerted on the 2.75-A wire. (b) Is the force per meter exerted on the 4.33-A wire greater than, less than, or the same as the force per meter exerted on the 2.75-A wire
Answer:
a)[tex]\frac{F_1}{L}=1.95*10^-^5N[/tex]
b)[tex]\frac{F_2}{L}=1.95*10^-^5N[/tex]
Explanation:
From the question we are told that:
Distance between wires [tex]d=32.2[/tex]
Wire 1 current [tex]I_1=2.75[/tex]
Wire 2 current [tex]I_2=4.33[/tex]
a)
Generally the equation for Force on [tex]l_1[/tex] due to [tex]I_2[/tex] is mathematically given by
[tex]F_1=I_1B_2L[/tex]
Where
B_2=Magnetic field current by [tex]I_2[/tex]
[tex]B_2=\frac{\mu *i_2}{2\pi d}[/tex]
Therefore
[tex]F_1=I_1B_2L[/tex]
[tex]F_1=I_1(\frac{\mu *i_2*l_1}{2\pi d})L[/tex]
[tex]\frac{F_1}{L} =\frac{4*\pi*10^{-7}*2.75*4.33*100 }{2*\pi*12.2 }[/tex]
[tex]\frac{F_1}{L}=1.95*10^-^5N[/tex]
b)
Generally the equation for Force on [tex]I_2[/tex] due to [tex]I_1[/tex] is mathematically given by
[tex]F_2=I_2B_1L[/tex]
Where
B_1=Magnetic field current by [tex]I_2[/tex]
[tex]B_1=\frac{\mu *I_1}{2\pi d}[/tex]
Therefore
[tex]\frac{F_2}{L} =I_2(\frac{\mu *I_1*I_2}{2\pi d})[/tex]
[tex]\frac{F_2}{L}=1.95*10^-^5N[/tex]
You and a friend are playing with a Coke can that you froze so it's solid to demonstrate some ideas of Rotational Physics. First, though, you want to calculate the Rotational Kinetic Energy of the can as it rolls down a sidewalk without slipping. This means it has both linear kinetic energy and rotational kinetic energy. [The freezing only matters because if there is liquid inside, the calculation for the Moment of inertia becomes more complicated]. A Coke can can be modeled as a solid cylinder rotating about its axis through the center of the cylinder. This can has a mass of 0.33 kg and a radius of 3.20 cm. You'll need to look up the equation for the Moment of Inertia in your textbook. It is rotating with a linear velocity of 6.00 meters / second in the counter-clockwise (or positive) direction. You can use this to determine the angular velocity of the can (since it is rolling without slipping). What is the Total Kinetic Energy of the Coke can
Answer:
K_{total} = 8.91 J
Explanation:
In this exercise you are asked to find the kinetic energy of the can of coca-cola
K_total = K_ {Translation} + K_ {rotation}
the translational kinetic energy is
K_ {translation} = ½ m v²
the kinetic energy of rotation is
K_ {rotation} = ½ I w²
The moment of inertia of a cylinder is
I = ½ m r²
we substitute
K_ {total} = ½ m v² + ½ (½ m r²) w²
angular and linear velocity are related
v = w r
we substitute
K_ {total} = ½ m v² + ¼ m r² v² / r²
K_ {total} = m v² (½ + ¼)
K_ {total} = ¾ m v²
let's calculate
K_ {total} = ¾ 0.33 6.00²
K_{total} = 8.91 J
A relaxed biceps muscle requires a force of 25.4 N for an elongation of 3.20 cm; under maximum tension, the same muscle requires a force of 520 N for the same elongation. Find Young's modulus (Pa) for the muscle tissue under each of these conditions if the muscle can be modeled as a uniform cylinder with an initial length of 0.200 m and a cross-sectional area of 50.0 cm2.
Answer:
Y = 31750 Pa = 31.75 KPa (For 24.5 N force)
Y = 312500 Pa = 312.5 KPa (For 250 N force)
Explanation:
Since the elongation is constant. Therefore, the strain will remain the same in both cases:
[tex]Strain = \frac{Elongation}{Original\ Length}\\\\Strain = \frac{0.032\ m}{0.2\ m}\\\\Strain = 0.16[/tex]
FOR A FORCE OF 25.4 N:
[tex]Stress = \frac{Force}{Area}\\\\Stress = \frac{25.4\ N}{0.005\ m^2}\\\\Sress = 5080\ Pa = 5.08\ KPa[/tex]
Now, for Young's Modulus:
[tex]Y = \frac{Stress}{Strain}\\\\Y = \frac{5080\ Pa}{0.16}[/tex]
Y = 31750 Pa = 31.75 KPa
FOR A FORCE OF 520 N:
[tex]Stress = \frac{Force}{Area}\\\\Stress = \frac{250\ N}{0.005\ m^2}\\\\Sress = 50000\ Pa = 50\ KPa[/tex]
Now, for Young's Modulus:
[tex]Y = \frac{Stress}{Strain}\\\\Y = \frac{50000\ Pa}{0.16}[/tex]
Y = 312500 Pa = 312.5 KPa
If acceleration is zero what statement about velocity is
true *
A)Velocity is zero
B)Velocity is constant
C)Velocity cannot be determined
D) Velocity is changing
Answer: A
Velocity is zero because the acceleration isn't affected, and velocity is the rate of change, so it can't be any other options.
Answer:
B)Velocity is constantExplanation:
If an object moves with a velocity and there is no acceleration, then the velocity remains constant. His velocity after five second will be equal to his initial velocity.#keeplearning dude:)The instantaneous speed of a cat running 400 meters in 20 seconds is 20 meters per second.
OTrue
O False
Answer:
true
Explanation:
400/20=20
Answer:
True
Explanation:
400/20=20mps
plz mark me as brainliest.
What type of electromagnetic radiation is being shown in the picture?
A. Gamma rays
B. Ultraviolet radiation
C. X-rays
D. Infrared radiation
Answer:
I think D. Infrared radiation.
Answer:
infrared radition
Explanation:
valid
A plano concave lens is one that has a surface that curves inward, making the lens thinner at its center than at its edges. Its effect on light is :_______.
a.) to make it appear as if incident parallel light is coming from a point close to the lens on the opposide side from the light source
b.) the diverge in incident beam of light
c.) to converge light to a focus
d.) to make it appear as if incident parallel light is coming from a point close to the lens on the same side as the light source
Answer:
b.) the diverge in incident beam of light
Explanation:
A lens refers to any refracting surface. The manner in which a lens is curved tells whether it is a concave(diverging) lens or a convex (converging) lens.
A convex lens is thicker at the center than at the edges. It makes light to converge at a point.
A concave lens is is thinner at the center than at the edges. It makes light to appear to diverge from a point, hence the answer above.
Which of the following is not a unit of speed *
a) m/s
b) km/s
c) mph [miles per hour]
d) light year
Answer:
I think it's light year but there shouldn't be also km/s but km/h
What is oscillating to form a light wave?
O Electric and Magnetic Fields
O Matter
O Light is only a particle, not a wave
O The Luminiferous Aether
Energy cannot be changed from one variety to another.
Explanation:
According to the law of conservation of energy, energy can neither be created nor destroyed but can be changed from one form to another.
for example : electrical energy can be converted or changed into light energy, sound energy, heat energy etc. this proofs that the law can be trusted because, it has just been proven by the example above that it can be changed and into many forms
Chemotherapy is used to treat
cervical cancer.
endometriosis.
undescended testicles.
benign prostatic hypertrophy.
Answer:
Cervical cancer
Explanation:
Chemotherapy is a common treatment or most cancers
Answer:
A
Explanation:
Can someone take there time and answer this :)
Answer: I think B.)
Explanation:
A level of
class one
has a length of
4m
and is
able
to lift
a load of 40kg with a force of 40N. Find
the position Of
fulcrum.
Answer:
x = 2 meters.
Explanation:
Let the position (distance) of fulcrum to the load be x.
Given the following data;
Load = 40 kg
Effort (force) = 40 Newton
Effort arm = 4 - x
To find the position of the fulcrum, we would use the expression;
Effort * effort arm = load * load arm
40 * (4 - x) = 40 * x
160 - 40x = 40x
160 = 40x + 40x
160 = 80x
x = 160/80
x = 2 meters
Therefore, the position (distance) of fulcrum to the load is 2 meters.