Determine the distance S to which the 90kg painter can climb without causing the 4m ladder to slip at it's lower end A. The top of the 15kg ladder has a small roller, and at the ground the coefficient of static friction is 0.25. The mass center of the painter is directly above her feet.
Answers
Explanation:
...................,..........
Newton's first law states that at rest the sum of the forces acting on a body is zero
The distance S to which the painter can climb is approximately 2.55 meters
The reason the above value for the distance is correct is as follows:
The given parameter are;
The mass of the painter, m₁ = 90 kg
Length of the ladder, l = 4 m
The mass of the ladder, m₂ = 15 kg
The coefficient pf static friction, μ = 0.25
Friction force, [tex]\mathbf{F_f}[/tex] = Normal reaction, N × μ
Normal reaction (flat surface), N = Weight of painter + Weight of ladder
N = m₁·g + m₂·g
Where;
g = The acceleration due to gravity, g = 9.81 m/s²
N = 90 kg × 9.81 m/s² + 15 kg × 9.81 m/s² = 1,030.05 N
∴ [tex]\mathbf{F_f}[/tex] = 1,030.05 N × 0.25 = 257.5125 N
Friction force, [tex]\mathbf{F_f}[/tex] = 257.5125 N (Horizontal force)
At equilibrium, the sum of the horizontal forces = 0
∴ Fₓ + [tex]\mathbf{F_f}[/tex] = 0
Fₓ = [tex]-F_f[/tex] = -257.5125 N (Acting opposite to the direction of the friction force)
The height of the top of the ladder from the ground, h = √(4²-1.5²) = √(13.75)
Taking moment about point A gives;
Clockwise moment = Anticlockwise moment
Fₓ × h = m₁·g·s·cos(θ) + m₂·g·(l/2)·cos(θ)
Therefore;
Fₓ × √(13.75) m = 90 kg × 9.81 m/s² × s × (1.5/4) + 15 kg × 9.81 m × 2 m × (1.5/4)
Fₓ × √(13.75) m = 331.0875 N × s + 110.3625 J
257.5125 N × √(13.75) m = 331.0875 N × s + 110.3625 J
s = (257.5125 N × √(13.75) m - 110.3625 J)/(331.0875 N) ≈ 2.55 m
The distance to which the 90 kg painter can climb without causing the 4 m ladder to slip at its lower end, A, distance S ≈ 2.55 meters
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Related Questions
A long, thin, insulated wire carries a current I1=1A out of the plane of the paper. The wire is surrounded by a long cylinder of radius a=12cm. The cylinder carries a current I2=9A that is unformly distributed over its cross section and flows into the plane of the paper.
Find the radius r at which the amgnetic field is zero.
Answers
Answer:
The magnetic field is zero at a radius r = 4 cm.
Explanation:
The magnetic field due to the wire is given by B₁ = μ₀I₁/2πr where I₁ = current in wire = 1 A and r = distance of point where magnetic field is zero from wire.
Now, since the current is uniformly distributed in the cross section of the cylinder, its current density is constant.
So, with current I₂ = 9 A flowing in the cylinder and radius, a = 12 cm. Let I' = current at radius r where the magnetic field is zero. So,
I'/πr² = I₂/πa²
I' = I₂r²/a²
Using Ampere's Law, the magnetic field B₂ at the distance r is given by
∫B.ds = μ₀I'
∫Bdscos0 = μ₀I' (since the magnetic field is parallel to the path)
B∫ds = μ₀I' ∫ds = 2πr
B2πr = μ₀I'
2Bπr = μ₀I₂r²/a²
B₂ = μ₀I₂r/2πa²
So, when the net magnetic field is zero, B₁ = B₂
So, μ₀I₁/2πr = μ₀I₂r/2πa²
I₁/r = I₂r/a²
I₁/I₂ = r²/a²
r² = I₁/I₂a²
taking square root of both sides,
r = a√(I₁/I₂)
substituting the values of the variables, we have
r = 12√(1/9)
r = 12/3
r = 4 cm
The magnetic field is zero at a radius r = 4 cm.
The relatively high resistivity of dry skin, about 1 × 106 O·m, can safely limit the flow of current into deeper tissues of the body. Suppose an electrical worker places his palm on an instrument whose metal case is accidentally connected to a high voltage. The skin of the palm is about 1.5 mm thick. Estimate the area of skin on the worker’s palm that would contact a flat panel, then calculate the approximate resistance of the skin of the palm.
Answers
Answer:
The area is [tex]A = 0.015 \ m^2 [/tex]
The resistance is [tex]R = 1.0 *10^{5} \ \Omega [/tex]
Explanation:
From the question we are told that
The relativity of dry skin is [tex]\rho = 1 * 10^6\ \Omega\cdot m[/tex]
The thickness of the skin is [tex]d = 1.5 \ mm = 1.5 *10^{-3} \ m[/tex]
Generally the area of a flat palm with length = 0.10 m and breath b = 0.15 m is mathematically represented as
[tex]A = d * L[/tex]
[tex]A = 0.10 * 0.15 [/tex]
[tex]A = 0.015 \ m^2 [/tex]
Generally the resistance is mathematically represented as
[tex]R = \frac{\rho * d}{ A }[/tex]
=> [tex]R = \frac{ 1.0 *10^{6} * 1.5*10^{-3}}{ 0.015 }[/tex]
=> [tex]R = 1.0 *10^{5} \ \Omega [/tex]
a battery-operated car moves forward as a result of which device?
Answers
Answer:
the wheels
Explanation:
Answer:
depends..
Explanation:
it can be Electromagnet or generator or a motor
Three equal point charges, each with charge 1.05 μCμC , are placed at the vertices of an equilateral triangle whose sides are of length 0.500 mm . What is the electric potential energy UUU of the system? (Take as zero the potential energy of the three charges when they are infinitely far apart.)
Answers
Answer:
The value is [tex]U = 0.06 \ J [/tex]
Explanation:
From the question we are told that
The value of charge on each three point charge is
[tex]q_1 = q_2 = q_3 =q= 1.05 \mu C = 1.05 *10^{-6} \ C[/tex]
The length of the sides of the equilateral triangle is [tex]r = 0.500 \ [/tex]
Generally the total potential energy is mathematically represented as
[tex]U = k * [ \frac{q_1 * q_2}{r} + \frac{q_2 * q_3}{r} + \frac{q_3 * q_1}{r} ][/tex]
=> [tex]U = k * 3 * \frac{q^2}{r} [/tex]
Here k is coulomb constant with value [tex]k = 9*10^{9}\ kg\cdot m^3\cdot s^{-4} \cdot A^{-2}.[/tex]
=> [tex]U = 9*10^9 * 3 * \frac{(1.05 *10^{-6})^2}{0.5 } [/tex]
[tex]U = 0.06 \ J [/tex]
URGENT URGENT DUE SOON!!
Which statement describes a question that can guide the design of a
scientific investigation?
A. It asks about a cause-and-effect relationship between two
variables.
B. It asks about the preferred outcome of the investigation.
C. It asks about whether a controlled variable is necessary.
D. It asks about how the observations will be organized.
Answers
Answer:
A.
Explanation:
Im just guessing because it sounds like it describes a hypothesis the most and you said its urgent
sam exerts a force of 65 N on a lawn mower with a mass of 25 kg. which formula can be used to calculate the acceleration of a lawn mower
Answers
Answer:
F = ma - with this you will get 2.6 m/s^2
Explanation:
Use this formula to get the acceleration...
where F is force, M is mass and A is acceleration
by using this we get...
65 = 25 * a
so, a = 65/25
Therefore, the acceleration is 2.6 m/s^2
Hope that helped :)
The acceleration of a lawn mower will be 2.6 m/s². It is the ratio of force and the mass.
What is acceleration?The rate of change of velocity with respect to time is known as acceleration. According to Newton's second law, the eventual effect of all forces applied to a body is its acceleration.
The given data in the problem is;
The force act on a lawn mower,[tex]\rm F = 65 \ N[/tex]
Mass of lawn mower,[tex]\rm m = 25 kg[/tex]
The acceleration of a lawn mower is,[tex]\rm a = ?[/tex]
Acceleration, is found as the ratio of force and the mass.
[tex]\rm F= ma \\\\ a = \frac{F}{m} \\\\ a= \frac{65}{25} \\\\ a = 2.6 \ m/s^2[/tex]
Hence, the acceleration of a lawn mower will be 2.6 m/s².
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A model airplane is flying north with a velocity of of 15m/s. A strong wind blowing east at 12m/s
What is the airplanes resultant speed (magnitude of vector)
What is the airplanes heading (direction of velocity vector
Answers
Answer:
1.) 19.21 m/s
2.) 57 degree
Explanation: Given that a model airplane is flying north with a velocity of of 15m/s. A strong wind blowing east at 12m/s
The airplanes resultant speed can be calculated by using pythagorean theorem
R = sqrt ( 15^2 + 12^2 )
R = sqrt( 225 + 144 )
R = sqrt( 369 )
R = 19.21 m/s
The magnitude of the resultant vector is 19.21 m/s
The direction of velocity vector will be:
Tan Ø = 15 /12
Tan Ø = 1.25
Ø = tan^-1(1.25)
Ø = 57.04
Ø = 57 degree.
Therefore, the airplanes is heading 57 degree in the horizontal direction of velocity vector
The position of a particular particle as a function of is given by r=(8.5t i+5.6j-2tk )m (a) Determine the particle’s velocity and acceleration as a function of time.
(b) Find the instantaneous velocity and acceleration of the particle at t=3.0 s.
Answers
Answer:
use google to find answer
Explanation:
69 69 69 69 69 69
The brakes of a car are applied, causing it to slow down at a rate of 10 ft/s2. Knowing that the car stops in 300 ft, determine
(a) how fast the car was traveling immediately before the brakes were applied,
(b) the time required for the car to stop.
Answers
Answer:
(a) The velocity of the car before the brakes were applied is 77.46 ft/s
(b) The time required for the car to stop is 7.8 s
Explanation:
Given;
acceleration of the car, a = 10 ft/s²
distance traveled by the car, d = 300 ft
(a) the velocity of the car before the brakes were applied is given;
v² = u² + 2ad
v² = 0 + 2(10 x 300)
v² = 6000
v = √6000
v = 77.46 ft/s
(b) the time required for the car to stop
d = ut + ¹/₂at²
d = 0 + ¹/₂at²
d = ¹/₂at²
t² = 2d / a
t = √ ( 2d / a)
t = √ ( 2 x 300 / 10)
t = 7.8 s
Therefore, the time required for the car to stop is 7.8 s
The speed of the car immediately before the brakes were applied was 77.46 ft/s and it took 7.75 s for the car to stop.
Using the formula:
v² = u² + 2as
Where S is the distance = 300 ft, u is the initial velocity, a is the acceleration = -10 ft/s², v is the final velocity = 0 ft/s (stops)
0² = u² + 2(-10)(300)
0 = u² - 6000
u² = 6000
u = 77.46 ft/s
b)
v = u + at
0 = 77.46 - 10t
t = 7.75 s
The speed of the car immediately before the brakes were applied was 77.46 ft/s and it took 7.75 s for the car to stop.
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An elevator held by a single cable is ascending but slowing down. Is the work done by tension positive, negative, or zero? What about the work done by gravity? Explain
Answers
Explanation:
1.) Work = Force*Distance
2.) The direction of motion lies in the same direction as the tension in the cable. So the work done by tension would be positive.
3.) The direction of the weight (due to gravity) would act opposite to the direction of motion of the elevator, so work done by gravity becomes negative.
If you push a book 1.5 m across a table using a constant force of 10.0 N, how much work do you
do on the book?
Answers
Answer:
The answer is
15.0 JExplanation:
To calculate the work done by a body we use the formula
work done = force × distanceFrom the question
force = 10 N
distance covered = 1.5 m
So the work done is
work done = 10 × 1.5
We have the final answer as
15.0 JHope this helps you
The Shinkansen (bullet train in Japan) makes a trip from Tokyo Station to Kyoto station in 2 hours and 14 min. The distance traveled is 460 km (to two significant figures). Determine the average velocity of the train in meters per second (m/s). [conversions: 1 km = 1000 m, 1 hr = 60 min, 1 min = 60 s] *
Answers
Answer:
v = 57.2 m/s
Explanation:
The average velocity of the train can be defined as the total distance covered by the train divided by the time taken by the train to cover that distance. Therefore, we will use the following formula to find the average velocity of the train:
v = s/t
where,
s = distance covered = 460 km = (460 km)(1000 m/1 km) = 4.6 x 10⁵ m
t = time taken to cover the distance = 2 h 14 min
Now, we convert it into minutes:
t = (2 h)(60 min/1 h) + 14 min
t = 120 min + 14 min = (134 min)(60 s/1 min)
t = 8040 s
Therefore, the value of velocity will be:
v = (4.6 x 10⁵ m)/8040 s
v = 57.2 m/s
A river flows from south to north at 5.6 km/hr. On the west bank of this river, a boat launches and travels perpendicular to the current with a velocity of 7.7 km/hr due east. If the river is 1.6 km wide at this point, how far downstream does the boat land on the east bank of the river relative to the point it started at on the west bank?
Answers
Answer:
Downstream displacement = 1.1648 km
Explanation:
Given:
Speed of flow = 5.6 km/h
Speed of current upstream = 7.7 km/h
Increase in size = 1.6 km wide
Computation:
Total time to cross = Increase in size / Speed of current upstream
Total time to cross = 1.6 / 7.7
Total time to cross = 0.208 h
Downstream displacement = Speed of flow × Total time to cross
Downstream displacement = 5.6 × 0.208
Downstream displacement = 1.1648 km
Velocity is the speed and direction of an object. true of false
Answers
Answer:
true
Explanation:
Because if u have seen many velocity videos or got taught it then u should know
In order to have good physical fitness, you __________. A. should be able to complete daily tasks without being physically taxed B. must be able to run a 4-minute mile C. need to work out at the gym four times a week D. don't need to worry about eating healthy foods
Answers
Answer:
A) should be able to complete daily tasks without being physically taxed
Explanation:
B) you dont need to run that fast to have good physical fitness
C) you dont need to workout four times a week
D) you should always eat healthy as diet contributes to health
In order to have good physical fitness, you should be able to complete daily tasks without being physically taxed.
What is physical fitness?Physical fitness is the ability to be fit to do work without getting tired easily.
Exercise and workouts are necessary to build and improve physical fitness.
Exercises required include jogging and running.
Therefore, in order to have good physical fitness, you should be able to complete daily tasks without being physically taxed.
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3) An explorer walks 13 km due east, then 18 km north, and finally 3 km west.
a) What is the total distance walked?
b) What is the resulting displacement of the explorer from the starting point?
Answers
Answer: 34 km, 21 km 61 degrees north of east
Explanation: distance = 13 + 3 + 18 = 34
displacement = 13 - 3 = 10
10^2 + 18^2 = 424
find the square root of 424 ( 20.5 rounded to 21 )
The total distance walked is 34 km and the resulting displacement is 20.6 km.
a) The total distance is gotten by summing up all the distance.
Total distance = Distance moved east + distance moved north + distance moved west
Total distance = 13 km + 18 km + 3 km = 34 km
b) The displacement is the distance from the beginning point to end point.
Displacement² = 18² + (13 - 3)² = 18² + 10²
Displacement² = 424
Displacement = 20.6 km
Therefore the total distance walked is 34 km and the resulting displacement is 20.6 km.
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Which is a benefit of using synthetic polymers, such as nylon?
Synthetic polymers are lightweight.
O Synthetic polymers are produced in small
quantities.
Synthetic polymers are biodegradable.
Synthetic polymers are inexpensive to recycle.
Answers
Answer: Synthetic polymers are lightweight.
Explanation:
A benefit of using synthetic polymers is the fact that synthetic polymers are lightweight.
A polymer is a molecule composed of many repeating subunits.
Synthetic polymers are artificial polymers created by humans.
Most of the synthetic polymers are not biodegradable (unlike natural fibers such as cotton).
Synthetic polymers are classified according to their use into plastics, elastomers and synthetic fibers.
The advantages of synthetic polymers include: hard to break, being lightweight, and they last for a long time.
In conclusion, a benefit of using synthetic polymers is the fact that synthetic polymers are lightweight.
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why does person feel weightlessness during freefall
Answers
Answer: the only force acting upon your body is the force of gravity
Explanation: a non-contact force. ... The force of gravity is the only force acting upon your body. There are no external objects touching your body and exerting a force. As such, you would experience a weightless sensation.
Explanation:
When in free fall, the only force acting upon your body is the force of gravity - a non-contact force. Since the force of gravity cannot be felt without any other opposing forces, you would have no sensation of it. You would feel weightless when in a state of free fall
Describing the Motion of an Object
SARE
Use the information from the graph to answer the
question.
What is the acceleration of the object?
m/s2
Velocity vs. Time
Velocity (m/s)
45
40
35
30
25
20
10
5
0
0
2
10
12
4. 6 8
Time (s)
Answers
Answer:
i actually dont know im so sorry but i will keep trying to find the answerr
1. What does the horizontal axis ordinarily oscilloscope? The vertical measure on an axis?
2. What frequency should the function generator be set to if period of 25 us is a desired?
Answers
Answer:
vertical axis measures voltage while
The horizontal axis of an oscilloscope measures time
2) we are told that Period
T = 25 microseconds = 25*10^-6 s
So we also know that
frequency f = 1/T
So
= 1/(25*10^-6)
= 40,000 Hz
Using the equation for for Newton's Second law, m=F/a solve the following problem. You have been given an object with a force of 10N and an acceleration of 2 m/s2, what is the mass?
Group of answer choices
1. 8g
2. 3g
3. 20g
4. 5g
Answers
Answer:
4. 5g
Explanation:
F=ma so, m=Fa. All you have to do is 10/2. Don't be confused by the units. Mass will normally be in grams.
Calculate the average speed between 0 s and 20 s
Answers
Answer:
2 m/s
Explanation:
The following data were obtained from the question:
Distance (D) = 40 m
Time (t) = 20 s.
Average speed =?
Average speed is the total distance travelled divided by the total time taken. Mathematically, it is expressed as:
Average speed = Total distance /Total time
Thus, we can obtain the average speed as follow:
Total Distance (D) = 40 m
Time time (t) = 20 s.
Average speed =?
Average speed = Total distance /Total time
Average spee= 40/20
Average speed = 2 m/s
Therefore, the average speed between 0 and 20 seconds is 2 m/s.
Suppose a radio signal (light) travels from Earth and through space at a speed of 3 × 10^8/ (this is the speed of light in vacuum). How far (in meters) into space did the signal travel during the first 10 minutes?
Answers
Answer:
Explanation:
we know that
s=vt here v is the speed and s is distance covered by the signals
given data
v=3*10^8
t=10 min we have to convert it into seconds
1 minute=60 seconds
so
10 minutes =10*60/1 =600 seconds
now putting the value of v and t we can find the value of s
s=vt
s=3*10^8*600
s=1.8*10^11m
i hope this will help you
Speed is the rate of distance over time.
The signal will travel [tex]1.8 \times 10^{11}[/tex] meters in the first 10 minutes
The given parameters are:
[tex]s = 3 \times 10^8\ ms^{-1}[/tex] ---the speed of light
[tex]t = 10\ min[/tex] -- the time of travel
The relationship between speed, distance (d) and time is:
[tex]s = \frac dt[/tex]
Make d the subject
[tex]d = s \times t[/tex]
Substitute values for t and s
[tex]d = 3 \times 10^8\ ms^{-1} \times 10\ min[/tex]
Convert minutes to seconds
[tex]d = 3 \times 10^8\ ms^{-1} \times 10 \times 60s[/tex]
So, we have:
[tex]d = 3 \times 10^8\ m \times 10 \times 60[/tex]
[tex]d = 18 \times 10^{10}m[/tex]
Rewrite as:
[tex]d = 1.8 \times 10^{11}m[/tex]
Hence, the signal will travel [tex]1.8 \times 10^{11}[/tex] meters in the first 10 minutes
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If all other things remain equal, which of the following changes to a closed circuit
would result in increased resistance to the flow of electric current?
Reducing the temperature of the conductor
Reducing the thickness of the conductor
Replacing the conductor with a more conductive material
Reducing the length of the conductor
Answers
Answer:
the answer is b reducing the thickness of the conductor
Explanation:
The resistance to electric current increases as the cross-section of the conductor is reduced, as the conductor is lengthened, and as the conductor is heated. Replacing the conductor with a less-conductive material increases the resistance as well.
Answer:
Reducing the thickness of the conductor
Explanation:
If a 65-kilogram astronaut exerts a force with a magnitude of
50. N on a satellite that she is repairing, the magnitude of the
force that the satellite exerts on her is
Answers
50N.
The magnitude of the reaction to any force is equal to the magnitude of the first force. (See Newton #3.)
The satellite will also apply the same magnitude of force ( 50 N ) but in opposite direction.
Given data:
The mass of astronaut is, m = 65 kg.
The magnitude of force exerted on the satellite is, F = 50 N.
In this problem, we will apply the Newton's Third Law of motion, which says that, "To every action, there is an equal and opposite reaction". Which means if any object (say object 1) apply some force on another object (say object 2), then the object 2 will also apply same magnitude of force on object 1, but it will be in opposite direction.
In the given problem, the satellite will also apply the same magnitude of force on Astronaut.
Which means,
F' = - F
F' = - 50 N.
Negative sign shows that the direction of force is opposite.
Thus, we can conclude that the satellite will also apply the same magnitude of force ( 50 N ) but in opposite direction.
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Understand that the acceleration vector is in the direction of the change of the velocity vector. In one dimensional (straight line) motion, acceleration is accompanied by a change in speed, and the acceleration is always parallel (or antiparallel) to the velocity. When motion can occur in two dimensions (e.g. is confined to a tabletop but can lie anywhere in the x-y plane), the definition of acceleration is
Answers
Answer:
a = √ (a_t² + a_c²)
a_t = dv / dt , a_c = v² / r
Explanation:
In a two-dimensional movement, the acceleration can have two components, one in each axis of the movement, so the acceleration can be written as the components of the acceleration in each axis.
a = aₓ i ^ + a_y j ^
Another very common way of expressing acceleration is by creating a reference system with a parallel axis and a perpendicular axis. The axis called parallel is in the radial direction and the perpendicular axis is perpendicular to the movement, therefore the acceleration remains
a = √ (a_t² + a_c²)
where the tangential acceleration is
a_t = dv / dt
the centripetal acceleration is
a_c = v² / r
Three different groups each measured the diameter of a CD three times (the actual diameter of a CD is 12.00cm). The class data is shown in the table. Which group(s) was the most accurate in their measurements? Group 1 only Group 1 only Group 2 only Group 2 only Group 3 only Group 3 only Groups 1 & 3 were equally accurate
Answers
Is steel considered matter
Answers
Answer:
yes. everything around you is matter including you!
Answer:
yes
Explanation:
because it takes up space
Acceleration occurs when velocity changes. O True O False
Answers
Answer:
True
Explanation:
Acceleration by definition is the change in velocity divided by the change in time. Thus when the velocity changes, there must be an acceleration.
The bird that migrates the farthest is the Arctic tern. Each year, the Arctic tern travels
32,000 km between the Arctic Ocean and the continent of Antarctica. Most of the
migration takes place within two four-month periods each year. Assume an Arctic
tern completes the second half of its annual migration distance in 122 days. Also
assume that during this time the tern flies directly north. If the tern flies the same
distance each day, what is its velocity in kilometers per day?
Answers
Answer: 131.14km per day
Explanation: since the second half of the terns migration takes 122 days we can assume that the full migration would take 244 days. using this we can divide the total distance by the total amount of days it takes (because speed = distance/time) which is 32,000/244, which would be 131.14