The steepest street in the world is Baldwin Street in Dunedin, NZ. It is inclined at an angle of 380 , with the horizontal. A child slides down the street with a constant velocity on a sled with high friction runners. What is the coefficient of friction between the sled runners and the street?
Answers
Newton's second law allows to find the result for the friction coefficient of the street is:
The friction coeficinwete is: μ = 0.78
Newton's second law establishes a relationship between the net force, the mass and the acceleration of the body.
∑ F = m a
Where bold indicates vectors, m is to mass and acceleration.
In the attached we see a free body diagram, it is a diagram of the forces without the details of the body, the x-axis is parallel to plane also shown with the positive in the direction of movement, going down the plane and the y-axis perpendicular to the plane.
Let's use trigonometry to break down the weight.
Sin θ = [tex]\frac{W_x}{W}[/tex]
cos θ = [tex]\frac{W_y}{W}[/tex] / W
Wₓ = W sin θ
[tex]W_y[/tex] = W cos θ
We write Newton's second law for each axis.
y-axis
N- [tex]W_y[/tex] = 0
N = mg cos θ
x-axis
Wₓ - fr = ma
Since they indicate that the body goes down at a constant speed, the acceleration is zero.
W sin θ = fr
The friction force is the macroscopic representation of the interactions between the two surfaces and the formula.
fr = μ N
we substitute.
fr = μ mg cos θ
mg sin θ = μ cos θ
μ = tan θ
Let's calculate.
μ = tan 38.0
μ = 0.78
In conclusion using Newton's second law we can find the results for the friction coefficient of the street is:
The frivtion coefficient is: μ = 0.78
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Related Questions
A 2.3 kg ball has 76 J of kinetic energy. How fast is it moving? Show all work and use correct units of measurement for the answer to get full credit.
Answers
Answer:
8.13 m/sExplanation:
The kinetic energy of an object can be found by using the formula
[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass in kg
v is the velocity in m/s
To find the velocity we make v the subject of the equation
That's
[tex]v = \sqrt{ \frac{2k}{m} } \\ [/tex]
From the question
k = 76 J
m = 2.3 kg
We have
[tex]v = \sqrt{ \frac{2 \times 76}{2.3} } = \sqrt{ \frac{152}{2.3} } \\ = 8.129388...[/tex]
We have the final answer as
8.13 m/sHope this helps you
Please Help
A car travels on a straight road with velocity components of 20 m/s west and 70 m/s south. What is the total distance the car travels in 50 s?
Answers
a cork floating in a beaker of water is attached to a spring, and the spring is attached to the bottom of the beaker. the spring pulls the cork farther below the water than it would be if it were just floating. what happens when we drop the beaker off a tall building?
Answers
Answer:
If we drop the beaker, due to inertia, the Cork will move upwards.
Option B is correct.
Explanation:
When we drop the beaker off a tall building, the cork attached to the spring moves in an upward direction.
What is spring force?Spring can be defined as a tool used for many purposes and its inertia is neglected by considering it is massless. When a spring is strained, undergoes displacement when it is compacted spring gets compressed but it can freely come to its equilibrium position.
Spring exerts an equal and an opposite force on a body that stretches or compresses it.
The Spring force formula can be written as:
F = k(x – x₀)
Where the spring force is F, xo is the equilibrium position, x is the displacement of the spring from the equilibrium position and the spring constant is k.
The negative sign shows that the spring force is a restoring force that acts in the opposite direction.
Therefore, the cork attached to the spring moves up when we drop the beaker off a tall building.
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What happens to the volume of a fixed amount of gas if both the pressure and the absolute temperature are doubled
Answers
Answer: no change in volume
Explanation:
[tex] \huge \mathcal{Question}[/tex]
Can someone Help me with this question ?
(I need proper Explanation if possible)
Thanks for Answering ~
Answers
Answer:
c. Force applied is 75 N
EDITED
tan 37 = a/g
a = 3g/4
a in equation
t× 3/5 = 2 × 3g/4
t = 5× 10/2
t = 25n
f = ma
f = ( mt + mb )a
F = 10 × 3× 10/4
F = 75 n
• Correct option is (C).
We know that the angle made by string is θ=
[tex]tan {}^{ - 1} ( \frac{a}{g} )[/tex]
where a is the acceleration of the frame in which the string is hanging in our case it is a trolley.
[tex]putting \: θ=37° \: or \: tan \: 37° = \frac{3}{4} [/tex]
[tex]we \: get \: a \: \frac{3g}{4} = \frac{30}{4} = 7.5 \: m/s^2[/tex]
[tex] \boxed{Force \: F=total \: mass \: of \: the \: system \: on \: which \: force \: is \: acting ×acceleration \: of \: the \: system=(8+2)×7.5=75 }[/tex]
[tex] \boxed{ so \: force \: is \: 75 \:N. }[/tex]
what is the medium for the sound waves for whales to communicate with each other?
Answers
Answer:
SONGS CLICKS AND WHISTLE
Explanation:
a force acting on 25kg mass produces an acceleration of 4m/square what would this the same force produce on a 12kg mass
Answers
Answer:8.3m/s
Explanation:
from F=ma, f=25*4=100N. since the force is 100, 100=12a. acceleration= 8.3m/s
What energy is used or given off by a fire?
Answers
Answer:
Heat is given off by Fire.
Explanation:
A satellite is orbiting Earth at a speed of approximately 4,000 m/s. Which of these distances is most likely the orbital radius of the satellite’s motion?
Answers
The radius of the satellite's motion is 2.49 × 10⁷ m
Since the centripetal force, F = mv²/r equals the gravitational force, F' = GMm/r² on the satellite,
F = F'
mv²/r = GMm/r²
v² = GM/r
Making r subject of the formula, we have
r = GM/v² where r = radius of satellite's motion, G = universal gravitational constant = 6.67 × 10⁻¹¹ Nm²/kg², M = mass of earth = 5.972 × 10²⁴ kg and v = speed of satellite = 4,000 m/s.
Substituting the values of the variables into the equation, we have
r = GM/v²
r = 6.67 × 10⁻¹¹ Nm²/kg² × 5.972 × 10²⁴ kg/(4,000 m/s)²
r = 39.83324 × 10¹³ Nm²/kg ÷ 16 × 10⁶ m²/s²
r = 2.4895775 × 10⁷ m
r ≅ 2.49 × 10⁷ m
So, the radius of the satellite's motion is 2.49 × 10⁷ m.
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Answer:
25.0 million meters
Explanation:
A car begins at rest at a stoplight. After the light turn green, the car begins to accelerate 5 m/s2 over the span of 3.6 seconds. What is the car’s displacement over this period of time?
Hint you can use this equation Xf = Xi + vi · t + 1/2 · a · t2
Answers
Answer:
d=9m
Explanation:
if a balloon is squeezed, what happens to the pressure of the gas inside the balloon?
Answers
Answer: By squeezing the balloon, you reduce the space the gas particles can occupy. As the particles are pushed a bit closer together, they collide with more, so the pressure from the moving gas particles increases. If the volume increases, its pressure decreases.
please help me thank you
Answers
Answer:
Refer to the attachment
A car starts from rest and for 15.0 s its wheels has a constant linear acceleration of 0.800 m/s^2 to the right. What is the angle through which each wheel rotated in 20.0 s interval if the radius of the tires is 0.330 m?
Answers
As the skydiver's ______increases, so does the magnitude of the force due to friction.
Answers
Answer:
speed?
Explanation:
give me more information
17. [06.05]
What particles are involved in nuclear reactions, but not in chemical reactions? (1 point)
Neutrons and protons
Neutrons and electrons
Protons and electrons
Electrons only
Answers
Answer:
What particles are involved in nuclear reactions, but not in chemical reactions? (1 point)
Ans Option A Neutrons and protons
22.13 .. Two very long uniform lines of charge are parallel and are separated by 0.300 m. Each line of charge has charge per unit length 5.20 mC>m. What magnitude of force does one line of charge exert o
Answers
Answer:
Two very long uniform lines of charge are parallel and are separated by 0.300 m. Each line of charge has charge per unit length.
Explanation:
I'LL MARK YOU BRAINLIST ......By referring to the graph shown below, the acceleration from t = 0 s to t = 25 s is:
positive
negative
zero
increasing
Answers
Answer:
When an object is speeding up, the acceleration is in the same direction as the velocity. Thus, this object has a positive acceleration. In Example B, the object is moving in the negative direction (i.e., has a negative velocity) and is slowing down.
Explanation:
Answer:
It’s zero.
Explanation:
It’s a straight line so its at a rest.
You and your friend are pushing a box at the same constant speed. You pushed 20 feet in 10 minutes, your friend was pushing for 5 minutes. What distance must she travel so the two of you can travel at the same speed?
Answers
Answer:
60 N.C
Explanation:
The box will move in the direction of the push and pull with a force of 60 N. C.
If you and your friend are pushing a box at the same constant speed. You pushed 20 feet in 10 minutes, your friend was pushing for 5 minutes. , then the distance must she travel so the two of you can travel at the same speed would be 30 feet.
What is speed?The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object.
As given in the problem If you and your friend are pushing a box at the same constant speed. You pushed 20 feet in 10 minutes, your friend was pushing for 5 minutes.
The distance traveled by box = 20 + 10
= 30 feets
Thus, the distance must she travel so the two of you can travel at the same speed would be 30 feet.
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help me out plssssssssssss
Answers
Answer:
1.b
2.c
have a good day bro
Which statement about a HORIZONTAL projectile is false?
The horizontal velocity is constant.
The horizontal acceleration is constant.
The vertical velocity is constant.
The vertical acceleration is constant.
Answers
Answer:
the vertical velocity is constant.
Explanation:
The horizontal velocity of a projectile is constant (a never changing in value), There is a vertical acceleration caused by gravity; thus, the vertical velocity of a projectile changes. and the horizontal motion of a projectile is independent of its vertical motion.
The total power input to the leaf blower is 750 W. The useful power outlet of the leaf blower is 360 W. Calculate the efficiency of the leaf blower.
Answers
H = Pu / P x 100% = 360/750 x 100% = 48%
P/s: Pu is the useful power outlet of the leaf blower
P is the total power input to the leaf blower
ok done. Thank to me :>
how to add ratio numbers can someone give me an exzample
Answers
Answer:
When the denominator of both ratios is the same, adding the ratio is simple. You just add the numbers to the left of the colon (this number is called the Ratio Numerator)xplanation:
Copper is a type of metal.
A block of copper has a mass of 2.0kg.
The block of copper absorbs 12000J of thermal energy.
The specific heat capacity of copper is 385J /(kg°C).
What is the temperature rise of the copper?
A 15.6°C B 31.2°C C 46.8°C D 62.4°C
Answers
The temperature rise in the copper is. I think its 0.393
The temperature rise in the copper is. I think its 0.393. Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29.
What is Capacity of copper?The chemical element copper (Cu) is a reddish, incredibly ductile metal belonging to Periodic Group 11 (Ib) that has an exceptional ability to conduct heat and electricity.
In nature, copper can be found in its free metallic state. Neolithic (New Stone Age) humans originally utilised this local copper (about 8000 BCE) as a substitute for stone.
Around 4000 BCE, Mesopotamia saw the beginning of metallurgy as copper was cast into molds, reduced to metal from ores with fire and charcoal, and purposefully alloyed with tin to form bronze (c. 3500 BCE).
Therefore, The temperature rise in the copper is. I think its 0.393. Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29.
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How is a controlled variable different from a responding variable? O A. A controlled variable changes due to changes in the responding variable during the experiment. B. A controlled variable stays the same throughout an experiment, but a responding variable changes, C. A controlled variable changes throughout an experiment, but a responding variable stays the same. O D. A controlled variable stays the same due to changes in the responding variable during the experient.
Answers
Answer:The controlled variable is the one that you keep constant. The responding variable or variables is what happens as a result of the experiment
Explanation:Mark me brainly please
Which of the following are for vector directione?
A Outside 45 degrees
G 35 degrees north of east
D 35 degrees inside
Answers
C. outside 45 degrees
Step-by-step explanation:
C. outside 45 degrees
because it can be any point or direction outside 45 degrees
What does the state of matter of an object depend on?
type of molecules
size of molecules
speed of molecules
number of molecules
Answers
Explanation:
A substance's state of matter — solid, liquid, gas, or plasma — depends on how its molecules move and maintain their volume and shape.
Please help!
What is momentum?
Answers
Answer:
a property of a moving body that the body has by virtue of its mass and motion and that is equal to the product of the body's mass and velocity
Explanation:
Formula:
Momentum: Mass x Velocity
Hope it helps!
251mL=25100L
True or false and why or why not?
Answers
Answer:
False
Explanation:
To find how many liters 251mL is you would need to divide 251 by 100 which is 0.251.
PLz help--- What's happening here?
This object is not moving
This object is not changing speeds.
This object is changing speeds; it's getting faster.
This object is changing speeds; it's getting slower.
Answers
Answer:
getting faster
Explanation:
the curve gets more steeper, and steeper line shows more distance for less time, meaning faster.
UV light has ______ wavelengths than visible light waves, and its peak energy is at a wavelength of ______.
Answers
Explanation:
Shorter wavelength since UV light has more energy than visible light
365 nm - What is the peak energy wavelength of UV light? It allows both infrared daylight and ultraviolet night-time communications by being transparent between 320 nm and 400 nm and also the longer infrared and just-barely-visible red wavelengths. Its maximum UV transmission is at 365 nm