Answers
If you take the positive horizontal direction to be to the right (the same direction as F₂), then by Newton's second law, the block has
• a net horizontal force of
∑ F = F₁ cos(-50°) + F₂ - f = m a
• a net vertical force of
∑ F = F₁ sin(-50°) + n - m g = 0
where
• f = µ n = magnitude of friction
• µ = coefficient of kinetic friction
• n = magnitude of the normal force
• m = 20 kg
• a = acceleration of the block
Solve for n :
n = m g + F₁ sin(50°)
n = (20 kg) (9.80 m/s²) + (50 N) sin(50°)
n ≈ 234.302 N
If the block accelerates uniformly from rest with acceleration a, then this acceleration is equal to its average, given by
a = ∆v / ∆t = (9 m/s - 0) / (3 s) = 3 m/s²
Solve for f :
f = F₁ cos(50°) + F₂ - m a
f = (50 N) cos(50°) + 80 N - (20 kg) (3 m/s²)
f ≈ 52.1394 N
Solve for µ :
µ = f / n
µ ≈ (52.1394 N) / (234.302 N)
µ ≈ 0.22253 ≈ 0.22
Related Questions
1 pts
Harry spent his summer playing guitar on the corner trying to earn some extra money. He would keep his guitar
case open for people to drop extra change into. Sometimes people would put money in the case and sometimes
people would be rude. Putting money in the hat is a to Harry's behavior.
Tir
Atte
1M
Negative reinforcement
Positive reinforcement
O Negative punishment
Positive punishment
Question 2
1 pts
O
SIC
acer
Answers
Answer:
Positive reinforcement
How much energy is needed to melt 150 g of ice at 0°C to water? (1)(Lf =3.34˟ 10⁵ J/Kg)
50 100 000J
50.1J
50 100J
501000 J
5 min
Answers
Answer:
5.01×10⁴ J.
Explanation:
Applying,
q = Cm....................... Equation 1
Where q = amount of heat needed to melt the ice, m = mass of the ice, C = specific latent heat of ice.
From the question,
Given: m = 150 g = (150/1000) kg = 0.15 kg, C = 3.34×10⁵ J/kg
Substitute these values into equation 1
q = (0.15×3.34×10⁵)
q = 0.501×10⁵ J
q = 5.01×10⁴ J.
The maximum allowable resistance for an underwater cable is one hundredth of an ohm per
meter and the resistivity of copper is 1.54 x 10-80m.
a) Calculate the smallest cross sectional area of copper cable that could be used.
Answers
Answer:
A = 1.54 x 10⁻⁵ m² = 15.4 mm²
Explanation:
The resistance of a wire can be given by the following formula:
[tex]R = \frac{\rho L}{A}\\\\A = \frac{\rho L}{R} = \frac{\rho}{\frac{R}{L} }[/tex]
where,
A = smallest cross-sectional area = ?
ρ = resistivity of copper = 1.54 x 10⁻⁸ Ωm
[tex]\frac{R}{L}[/tex] = resistance per unit length of wire = 0.001 Ω/m
Therefore,
[tex]A = \frac{1.54\ x\ 10^{-8}\ \Omega m}{0.001\ \Omega/m}[/tex]
A = 1.54 x 10⁻⁵ m² = 15.4 mm²
if the reading of a mercury barometer is 75.58cm at the base of a mountain and 66.37cm at the summit,what is the height of the mountain? (density of mercury= 13600kg/m³, average density of air=1.25kg/m³
Answers
Answer:
Explanation:
What are the benefits of 3D design and 3D printing software?
The height of the mountain is 1002.048 m.
What is pressure?The perpendicular force per unit area, or the stress at a point within a confined fluid, is referred to as pressure in the physical sciences.
Atmospheric pressure is the force of the atmosphere pressing down on each square meter of Earth's surface. Pascals are used to express pressure in SI units; one pascal is equivalent to one newton per square meter.
Given parameters:
at the base of a mountain, the reading of a mercury barometer is = 75.58cm = 0.7558 m.
at the summit of a mountain, the reading of a mercury barometer is = 66.37cm = 0.6637 m.
Let the height of the mountain = h.
Then,
h × density of air × g = ( 0.7558 - 0.6637) m × density of mercury × g
⇒ h × 1.25kg/m³ = 0.0921 m × 13600kg/m³
⇒ h = 1002.048 m.
Hence, the height of the mountain is 1002.048 m.
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54. Which of the following behaviors is most closely
associated with the foot-in-the-door phenomenon?
(A) Beth continues to participate in class because
she is positively reinforced.
(B) Adam is sleeping while the rest of his
classmates are working on their group
project
(C) Sutan asks his father for $5, and when he
agrees, Sutan asks him for $15 more.
(D) James feels pressure to go to the movies with
his friends even though he prefers to go
bowling.
(E) Diana feels guilty because she did not help
her family clear the table after dinner.
Answers
Answer:
C
Explanation:
Foot-in-the-door technique is a compliance tactic that aims at getting a person to agree to a large request by having them agree to a modest request first
The behavior that should be closely associated is option c. Sutan asks his father for $5, and when he agrees, Sutan asks him for $15 more.
What is the foot-in-the-door phenomenon?It is a tactic of compliance that focuses on agreeing on the person by having a request.
It shows the connection that lies between the person who is asking for a request and the person who is being asked.
So based on this, option c is correct.
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We know the mass and luminosity of the star. We also know the mass of the spacecraft and the area of its stellar sail. We must find the net force exerted on the spacecraft, as well as the direction of its acceleration. We are asked to find both the net force exerted on the spacecraft and the direction of the acceleration. Which principle is best used to find the direction of the acceleration once the net force has been found
Answers
Answer:
Newton's principle of force, the variation of the momentum and the acceleration have the same direction
Explanation:
To find the force exerted by the star on the sail of the ship, the expression of the momentum of the radiation is used, which in the case of a total reflection
p = [tex]\frac{2U}{c}[/tex]
where p is the momentum and U the incident energy and c the speed of light.
The strength I could get from
F = [tex]\frac{dp}{dt}[/tex]
the direction of the acceleration is the direction of the momentum, therefore the principle to find the acceleration of is Newton's principle of force, the variation of the momentum and the acceleration have the same direction.
When an object is put into a liquid, it experiences a buoyant force that is equal to the weight of the liquid the object displaces. The force on the wire is given as the block is slowly lowered into the liquid (position is given in "centimeters", which you have to change to "meters") and force is given in "newtons"). Choose a mass of the block between 0.125 kg and 0.375 kg and a density of the liquid between 500 kg/m^3 and 1000 kg/m^3. The object is in static equilibrium when the clock stops.
Required:
a. What is the weight of the block and the tension, F, in the string when the block is in the liquid?
b. What is the volume of the block in the liquid—either the submerged part of the block if the block is partially submerged when you paused it or the entire block if it is completely submerged (the dimension of the block that is into the screen is 5.00 cm = 0.0500m)?
c. What is the volume of the water that is displaced by the block (the dimension of both water containers into the screen is 10.00 cm = 0.100m)?
Answers
Answer:
A) F = 1.8375 N, B) V = 1.25 10⁻⁴ m³, C) V= 1.25 10⁻⁴ m³
Explanation:
This exercise should select some values such as the weight of the block m=0.250 kg and the density of the liquid ρ = 500 kg / m³ (water); with these values answer the question, for this we use the static equilibrium relations.
Σ F = 0
F + B - W = 0
the expression for thrust is
B = ρ g V_liquid
A) the weight of the block is
W = m g
W = 0.250 9.8
W = 2.45 N
Let's look for the maximum push
V_body = V_liquid
B = 500 9.8 0.05³
B = 0.6125 N
we substitute
F = W - B
F = 2.45 - 0.6125
F = 1.8375 N
B) As the body is totally submerged, the volume of the liquid and the body are equal
V = l³
V = 0.05³
V = 1.25 10⁻⁴ m³
C) the volume of water displaced is equal to the volume of the body
V_liquid = 1.25 10⁻⁴ m³
An automobile traveling at a speed of 28.3 m/s applies its brakes and comes to a stop in 4.9 s. If the automobile has a mass of 1.1 x 103 kg, what is the average horizontal force exerted on it during braking? Assume the road is level.
Find Magnitude and direction
WILL GIVE BRAINLIEST
Answers
Answer:
i say it would be 32.5 m if the brakes comes and stops. the road is 3.7 x 105
Explanation:
The chart shows the masses of selected particles.
Particle
Mass
2350
137 9 u
6
92
138
Ba
K:
on
94.9u
1.0 u
In the equation u + Ön – 133Ba + K+ + 36n+E , the energy E is equivalent to a mass of
1.
0.2 u
2.
2.0 u
3.
2.2 u
4.
0.0 u
Answers
Answer: 0.2 u
Explanation:
The atomic mass of nuclide is written as a superscript. On the left (reactants) aide of the nuclear equation shown, the total atomic mass is 235.0 + 1.0 u = 236 u. On the right (products) side reaction, the total atomic mass is 137.9u + 94.9u + 3 x 1.0u = 235.8 u. Therefore, 0.2 mass units must have been converted into energy.
what must happen for a electromagnet to have a magnetic field
Answers
a spring has a spring constant of 330 n/m. how far is the spring compressed when 150 newtons of force are used?
a. 0.0014 meters
b. 0.45 meters
c. 2.2 meters
d. 5.0 meters
show your work.
Answers
Answer:
b. 0.45 meters
Explanation:
Given the following data;
Spring constant, k = 330 N/m
Force = 150 N
To find the extension of the spring;
Mathematically, the force exerted on a spring is given by the formula;
Force = spring constant * extension
Substituting into the formula, we have;
150 = 330 * extension
Extension, e = 150/330
Extension, e = 0.45 meters
The diagram shows two
charged objects, X and Y.
Based on the field lines, what are the charges of the
objects?
X: positive
Y: negative
O X: negative
Y: positive
O x: negative
Y: negative
O x: positive
Y: positive
Answers
Answer:
X: positive
Y: positive
Explanation:
The electrical field lines have a specified direction based upon the sign of the charge. The electrical field lines have a direction coming out of the charge if the sign of the charge is positive. While the electrical field lines have a direction going inside the charge if the sign of the charge of negative.
It can be clearly seen in the diagram that the electric field lines are coming out of both charges. Therefore, both the charges are positive.
Hence, the correct option is:
X: positive
Y: positive
A physics student was studying falling bodies and decided to drop a water balloon from an outdoor stairwell to measure its speed. If the balloon was dropped a distance of 6 meters and it only took 1.1 seconds to fall, how fast was the balloon traveling on average? A. 0.2 m/s B. 6.6 m/s C. 5.5 m/s D. 66 m/s
WILL NAME BRAINLIEST
Answers
Answer:
C. 5.5 m/s
Explanation:
How fast the balloon travels is determined from the velocity or v
The formula is v = s/t or velocity equals distance divided by time
So, v = 6 meters divided by 1.1 seconds = 5.5 meters per second
Answer:
C. 5.5 m/s
Explanation:
How fast the balloon travels is determined from the velocity or v
The formula is v = s/t or velocity equals distance divided by time
So, v = 6 meters divided by 1.1 seconds = 5.5 meters per second
Answer the following question according to formal grammatical rules.
Which of the following sentences corrects the pronoun errors in this sentence?
If a person wants to help their community, they should research opportunities.
A. If a person wants to help their community, you should research opportunities.
B. If you want to help your community, a person should research opportunities.
C. If people want to help their community, they should research opportunities.
D. If a person wants to help it, they should research opportunities.
Answers
If people want to help their community, they should research opportunities corrects the pronoun errors in this sentence.
What is a Pronoun?This is defined as a word which is used instead of a noun and examples include he, she etc.
In this scenario, the word 'people' agrees with the possessive adjective 'their' and the personal pronoun 'they', which is referred to the third-person plural hence the reason why option C is the most appropriate choice.
Read more about Pronoun here https://brainly.com/question/26257764
Answer:
D
Explanation:
D
In A. C. motor capacitor is used
p.Can dicouly [BPKIHS 2000
to reduce ripples b. to decrease A. C.
c. to increase A. C. d. to decrease D. C.
a.
34
Answers
Answer:
d. to decrease D. C.
Explanation:
d. to decrease D. C.
A car comes to a stop six seconds after the driver applies the brakes. While the brakes are on, the following velocities are recorded:
Time since brakes applied (sec) 0 2 4 6
Velocity (ft/s) 87 44 16 0
Give lower and upper estimates (using all of the available data) for the distance the car traveled after the brakes were applied.
Answers
Answer:
Explanation:
deceleration during first 2 s = (87 - 44) / 2 =21.5 m /s²
deceleration during next 2 s = (44 - 16) / 2 =14 m /s²
deceleration during last 2 s = (16 - 0) / 2 = 8 m /s²
If we assume the acceleration to be uniform during 3 readings
distance travelled during first 2 s
v² - u² = 2 a s
87² - 44² = 2 x 21.5 x s
s = 7569 - 1936 / 43
= 176 m
distance travelled during next 2 s
44² - 16² = 2 x 14 x s
s = 1936 - 256 / 28
= 60 m
distance travelled during last 2 s
16² - 0² = 2 x 8 x s
s = 256 / 16
= 16 m
Total distance travelled = 176 + 60 + 16 = 252 m
If we assume the acceleration as non- uniform , we first calculate average acceleration as follows .
average acceleration = (87 - 0)/ 6 = 14.5 m /s²
v² - u² = 2 a s
87² - 0² = 2 x 14.5 x s
s = 7569 / 29
= 261 m
Hence lower estimate of distance travelled = 252 m ; upper estimate of distance travelled = 261 m .
Will award brainliest and upvote if you can help answer!
Answers
Answer:
Omqnp
Explanation:
I have done this before and got it correct
1The specific heat of substance (X) is greater than that for substance (Y). If equal amounts of heat are added to both these substances, the one reaching the higher temperature(assuming no phase change occurs for either) will be:
1. substance X
2. substance Y
3.there will be no difference in the final temperature.
4.both X and Y
Answers
Answer:
Substance Y
Explanation:
A substance with a high specific heat capacity can absorb a large quantity of heat before it will raise in temperature. A substance with a low specific heat requires relatively little heat to raise its temperature. Thus, if the same amount of energy was added to both substances, substance Y will reach the higher temperature, while substance X would require more energy to reach high temperatures.
Answer:
2. substance Y
Explanation:
specific heat is how much heat is needed to warm up something. Y has smaller specific heat means it warm up more w/ same amount of heat.
The block A and attached rod have a combined mass of 50 kg and are confined to move along the guide under the action of the 796-N applied force. The uniform horizontal rod has a mass of 15 kg and is welded to the block at B. Friction in the guide is negligible.
Required:
Compute the bending moment M exerted by the weld on the rod at B. The bending moment is positive if counterclockwise, negative if clockwise.
Answers
Answer:
The bending moment is 459.16 N.m
Explanation:
From the given information;
Let's assume that the angle is 66°
Then, the free body diagram is draw and attached in the file below.
Now, the calculation of the acceleration from the first part of the free body diagram is:
[tex]\sum F_x = ma_x \\ \\ 796 - 50(9.81) sin 66=50a \\ \\ 796 - 448.094 = 50 a \\ \\ a = \dfrac{347.906}{50} \\ \\ a = 6.96 \ m/s^2[/tex]
Bending moment M:
From the second part of the diagram:
[tex]\sum M_B = mad \\ \\ M - (15 \times 9.81) (1.5) = (25 \times 6.96)(1.5 sin 66) \\ \\ M - 220.725 = 238.435 \\ \\ M = 238.435 + 220.725 \\ \\ \mathbf{M = 459.16 \ N.m}[/tex]
A 1.55 kg frictionless block is attached to an ideal spring with force constant 340 N/m . Initially the spring is neither stretched nor compressed, but the block is moving in the negative direction at 14.0 m/s.
A.) Find the amplitude of the motion.
B.) Find the maximum acceleration of the block.
C.) Find the maximum force the spring exerts on the block.
Answers
Answer:
Explanation:
Let amplitude be A . At displacement A , velocity will be zero , so
1/2 k A² = 1/2 m v²
340 A² = 1.55 x 14²
A = .9452 m
= 94.52 cm
B ) angular frequency of oscillation ω = √ ( k / m )
= √ ( 340 / 1.55 )
ω = 14.81 radian /s
maximum acceleration = ω²A
= 14.81² x 0.9452
= 207.32 m/s²
C) Maximum force = mass x maximum acceleration
= 1.55 x 207.32
= 321.36 N .
Photons with the highest frequency have the lowest _____.
A. wavelength
B. speed
C. color
D. energy
Answers
Answer:
a wavelength
Explanation:
A bicyclist at the top of a hit begins to coast without pedaling. The bicycle speeds up as it descends to the bottom of the hill and then slows down as it continues
up a second, where it stops. Which of these sequences best describes the energy change of the bicycle from the top of the hill until it stops?
A.potential - kinetic-kinetic
B.Kinetic -potential -potential
C.Kinetic -potential -Kinetic
D.potent - Kinetic -potential
Answers
When a species has no members left that are alive
Answers
Answer:
it means that species is extinct.
Explanation:
have a good day :)
A 1.6-lb collar is attached to a spring and slides without friction along a circular rod in a vertical plane. The spring has an unstretched length of 6 in. The collar is released from being held at A, and it passes ponit B with a speed of 16.0 ft/s. Determine the spring constant. The circular rod is kept from moving.
Answers
Answer:
k = 652 lb/ft
Explanation:
Given :
Weight of the collar = 1.6 lb
The upstretched length of the spring = 6 in
Speed = 16 ft/s
PA = 8 + 10
= 18 inch
Let the initial elongation be [tex]$\Delta x_i$[/tex]
∴ [tex]$\Delta x_i$[/tex] = 18 - 6
= 12 inch = 1 foot
[tex]$PB = \sqrt{13^2+5^2}$[/tex]
= 13.925 inch
Final elongation in the spring
[tex]$\Delta x_B = 7.928 $[/tex] inch = 0.66 feet
Applying the conservation of the mechanical energy between A and B is
[tex]$K.E_A+P.E_{g,A}+P.E_{sp,A}= K.E_B+P.E_{g,B}+P.E_{sp,B} $[/tex]
[tex]$0+mg_r+\frac{1}{2}k(\Delta x_i)^2=\frac{1}{2}mv_B^2+0+\frac{1}{2}k(\Delta x_B)^2$[/tex]
[tex]$\frac{1}{2}k[(1)^2-(0.66)^2]=\frac{1.6}{2}\times (16)^2-1.6 \times 32 \times \frac{5}{12}$[/tex]
[tex]0.281 \ k =204.8-21.33[/tex]
k = 652 lb/ft
Starting from rest, a car takes 2.4 s to travel the first 15 m. Assuming a constant acceleration, how long will it take the car to travel the next 15 m?
Answers
Answer:
The time it will take the car to travel the next 15 m is 1 s.
Explanation:
Given;
initial velocity of the car, u = 0
time of motion, t = 2.4 s
initial distance traveled, d = 15 m
determine the constant acceleration of the car;
d = ut + ¹/₂at²
15 = 0 + (0.5 x 2.4²)a
15 = 2.88a
a = 15 / 2.88
a = 5.21 m/s²
The velocity of the car at the end of the first 15 m
v - u + at
v = 0 + 5.21 x 2.4
v = 12.5 m/s
The time to cover the next 15 m;
d₂ = vt + ¹/₂at²
15 = 12.5t + (0.5 x 5.21)t²
15 = 12.5t + 2.61t²
0 = 2.61t² + 12.5t - 15
Use the formula method to solve the above quadratic equation.
a = 2.61
b = 12.5
c = -15
[tex]t = \frac{-b \ \ +/- \ \ \sqrt{b^2 - 4ac} }{2a} \\\\t = \frac{-12.5 \ \ +/- \ \ \sqrt{12.5^2 - (4\times 2.61 \times -15)} }{2\times 2.61}\\\\t = 0.9937 \ s \ \ \ or \ \ \ -5.78 \ s\\\\time \ can \ only \ be \ positive;\\\\t \approx \ 1\ s[/tex]
Therefore, the time it will take the car to travel the next 15 m is 1 s.
When oxygen in water interacts with iron it results in O A rust forming O B) a chemical change C) oxidation O D) all of the above
Answers
Who serves as the presiding officer of the Senate?
Answers
Who serves as the presiding officer of the Senate?
[tex]{ \bf{ \underbrace{Answer :}}}[/tex]
The [tex]\sf\purple{Vice\:President}[/tex] of the United States serves as the presiding officer of the Senate.
At present, [tex]\sf\red{Kamala\:Harris}[/tex] is the president of the Senate.
[tex]\bold{ \green{ \star{ \orange{Hope\:it\:helps.}}}}⋆[/tex]
12. 2007: The figure below show two identical trollbys with loads A and B. The
loads are identical in shape and size.
D
Given that the density of A is greater than that of B, explain why the
trolley in figure 3 (in) is more stable
Answers
Answer:
you need to provide a figure that came with the problem.
Two identical thermally insulated spherical tanks, A and B, are connected by a valve. Initially tank A contains 20mol of an ideal diatomic gas, tank B is evacuated, and the valve is closed.
If the valve is opened and the gas expands isothermally fromA to B, what is the change in the entropy of the gas?
Answers
Answer:
Explanation:
Volume of gas is doubled isothermally . Let the temperature of the gas be T .Work done by the gas
W = 2.303 nRT log 2 V / V
Since expansion is isothermal , Δ E = 0
Q = ΔE + W
Q = W
Q = 2.303 nRT log 2 V / V
Q / T = 2.303 n R log 2
Change in entropy = ΔS = Q / T = 2.303 n R log 2
= 2.303 x 20 x 8.3 x .3010 J T⁻¹.
= 115 J T⁻¹.
The required change in the entropy of the gas is 115 J/K.
Given data:
The number of moles of diatomic gas in tank A is, n = 20 mol.
The expansion takes place isothermally, which means the volume is doubled at the constant temperature. Therefore, work done during the isothermal expansion is,
W = 2.303 nRT log 2 V / V
Since expansion is isothermal , Δ E = 0. Then by using the first law of thermodynamics as,
Q = ΔE + W
Q = W
Q = 2.303 nRT log 2 V / V
Q / T = 2.303 n R log 2
Also, we that the expression for the change in Entropy is,
ΔS = Q / T = 2.303 n R log 2
Solving as,
ΔS = 2.303 x 20 x 8.3 x .3010
ΔS = 115 J/K
Thus, we can conclude that the required change in the entropy of the gas is 115 J/K.
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A house is advertised as having 1460 square feet under roof. What is the area of this house in square meters?
Answers
Answer: 131.92 m
Explanation: The problem give above is a conversion problem. To convert any measurement from one unit to another, we need a relation for the original units to that of the desired unit. This relation is called the conversion factor. It is used by multiplying or dividing the factor depending on what is the unit of the original measurement. For this case, we need to convert from ft^2 to m^2. The conversion factor would be 1 foot is equal to 0.3048 m. So, we would be getting the square of the factor and then multiply to the original value.
1420 ft^2 ( 0.3048 m / 1 ft)^2 = 131.92 m