Answer:
F = 156.3 N
Explanation:
Let's start with the top block, apply Newton's second law
F - fr = 0
F = fr
fr = 52.1 N
Now we can work with the bottom block
In this case we have two friction forces, one between the two blocks and the other between the block and the surface. In the exercise, indicate that the two friction coefficients are equal
we apply Newton's second law
Y axis
N - W₁ -W₂ = 0
N = W₁ + W₂
as the two blocks are identical
N = 2W
X axis
F - fr₁ - fr₂ = 0
F = fr₁ + fr₂
indicates that the lower block is moving below block 1, therefore the upper friction force is
fr₁ = 52.1 N
fr₁ = μ N
a
s the normal in the lower block of twice the friction force is
fr₂ = μ 2N
fr₂ = 2 μ N
fr₂ = 2 fr₁
we substitute
F = fr₁ + 2 fr₁
F = 3 fr₁
F = 3 52.1
F = 156.3 N
unequal length of day and night
Rotation or Revolution
1) the wavelengths property that makes it possible for sound to be heard around a bend is A) diffraction. B) Reflection C) refraction. D) interference
2) which property of sounds do bats use to detect their paths?
A) Diffraction B) reflection C) Refraction D) interference
please give a reason or an explanation for each answer you choose
Answer:
1. A
2. B
Explanation:
Sound are mechanical waves that are highly dependent on matter for their propagation and transmission.
Sound travels faster through solids than it does through either liquids or gases.
Wavelength can be defined as the distance from one peak to the next peak of a waveform. This distance is also equal to the distance from one trough of a wave to another.
Diffraction is a wavelength property that makes it possible for sound to be heard around a bend. Thus, it's a property that causes a change in the direction of a wave as it travels through or around a barrier (obstacle) in its path.
Simply stated, diffraction involves the bending of waves around small obstacles with their dimensions smaller than or approximately equal to the wavelength of the sound wave.
On the other hand, reflection can be defined as a phenomenon which typically involves a change in the direction of a wave (bounces back) as it falls on a surface.
Hence, reflection is the property of sounds which animals such as bats use to detect their paths as they navigate from one point to another. This phenomenon is generally referred to as echolocation and it typically involves the use of reflection (echo) of sound to gain information about the nature and location of surrounding objects.
This is the last 2 questions i need! It’s due in 10 minutes please help!! I will mark brainliest asap
Answer:
I don't know 11 but in no. 10,
The ans is 3.66
Total distance = 10m+30m+15m = 55m
Total time = 5secs+7secs +3secs =15secs
Av speed = d/t =55/15 = 3.66 m/s
How does an electric bulb work?
this is a class 6 question...
Answer:
Explanation:
When a light bulb connects to an electrical power supply, an electrical current flows from one metal contact to the other. As the current travels through the wires and the filament, the filament heats up to the point where it begins to emit photons, which are small packets of visible light.
help me with the question b.
Answer:
a) The specific heat capacity means the amount of heat needed by a unit mass of a material to increase its temperature in one unit.
b) Liquid P - [tex]Q = 3840\,J[/tex], Liquid Q - [tex]Q = 5500\,J[/tex], Liquid R - [tex]Q = 7800\,J[/tex], Liquid S - [tex]Q = 2856\,J[/tex]
Explanation:
a) The specific heat capacity means the amount of heat needed by a unit mass of a material to increase its temperature in one unit.
b) Let suppose that heat transfer rates between liquids and surroundings are stable. The quantity of the heat released is determined by the following expression:
[tex]Q = m\cdot c\cdot (T_{r} - T_{f})[/tex] (1)
Where:
[tex]m[/tex] - Mass of the liquid, in kilograms.
[tex]c[/tex] - Specific heat capacity, in joules per kilogram-degree Celsius.
[tex]T_{r}[/tex] - Initial temperature of the sample, in degrees Celsius.
[tex]T_{f}[/tex] - Freezing point, in degrees Celsius.
Liquid P ([tex]m = 1\,kg[/tex], [tex]c = 160\,\frac{J}{kg\cdot ^{\circ}C}[/tex], [tex]T_{r} = 30\,^{\circ}C[/tex], [tex]T_{f} = 6\,^{\circ}C[/tex])
[tex]Q = (1\,kg)\cdot \left(160\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (30\,^{\circ}C - 6\,^{\circ}C)[/tex]
[tex]Q = 3840\,J[/tex]
Liquid Q ([tex]m = 1\,kg[/tex], [tex]c = 220\,\frac{J}{kg\cdot ^{\circ}C}[/tex], [tex]T_{r} = 30\,^{\circ}C[/tex], [tex]T_{f} = 5\,^{\circ}C[/tex])
[tex]Q = (1\,kg)\cdot \left(220\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (30\,^{\circ}C - 5\,^{\circ}C)[/tex]
[tex]Q = 5500\,J[/tex]
Liquid R ([tex]m = 1\,kg[/tex], [tex]c = 300\,\frac{J}{kg\cdot ^{\circ}C}[/tex], [tex]T_{r} = 30\,^{\circ}C[/tex], [tex]T_{f} = 4\,^{\circ}C[/tex])
[tex]Q = (1\,kg)\cdot \left(300\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (30\,^{\circ}C - 4\,^{\circ}C)[/tex]
[tex]Q = 7800\,J[/tex]
Liquid S ([tex]m = 1\,kg[/tex], [tex]c = 102\,\frac{J}{kg\cdot ^{\circ}C}[/tex], [tex]T_{r} = 30\,^{\circ}C[/tex], [tex]T_{f} = 2\,^{\circ}C[/tex])
[tex]Q = (1\,kg)\cdot \left(102\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (30\,^{\circ}C - 2\,^{\circ}C)[/tex]
[tex]Q = 2856\,J[/tex]
Q7 Explain how light can be reflected at lots of different angles from a rough surface and still obey the law of reflection. Use a diagram in your answer.
Q8 Read the following statements.
A: You can have refraction without dispersion
B: You cannot have dispersion without refraction
a Discuss a situation where statement A is true.
b Discuss a situation where statement B is true.
Q9 A light year is the distance that light travels in a year. It takes light about 8.3 minutes (or 500 seconds) to travel the 150 million km from the Sun. a Calculate how far light travels in 1 second.
b The Moon is 1.3 light seconds from Earth. Calculate how far away it is in km.
Explanation:
Q7Answer=If light meets a rough surface, each ray obeys the law of reflection. However, the different parts of the rough surface point in different directions, so the light is not all reflected in one direction. Instead, the light is reflected in all directions. This is called diffuse scattering .
dimension of radius of sphere
Answer:
The dimension is L
Explanation:
Dimension analysis is a method of representing quantities majorly with respect to some fundamental quantities of mass (M), length (L), time (T).
A sphere has a definite volume which relates to its radius by:
V = [tex]\frac{4}{3}[/tex][tex]\pi[/tex][tex]r^{3}[/tex]
In this equation [tex]\pi[/tex] is a dimensionless quantity, and the unit of v is [tex]m^{3}[/tex].
But, metre is a measure of length, thus it has a dimension of L.
So that,
[tex]m^{3}[/tex] ≅ [tex]L^{3}[/tex]
Then,
[tex]L^{3}[/tex] = [tex]r^{3}[/tex]
Find the cube root of both sides to have,
r = L
Therefore, the dimension of the radius of a sphere is L.
The diagram show three different types of walls that could be built in a house. Through which hall would the heat lost be maximum.
Answer:
the thin steel wall because that wall is so very to fast broke
You have recently been called to troubleshoot network connectivity problems at a user's workstation. You have found that the network cable runs across high-traffic areas on the floor, causing the cable to wear through and break. You have replaced the cable with a plenum-rated and shielded twisted pair cable. You would like to minimize the problem and prevent it from happening again.Which of the following will BEST protect the cable from further damage?A. Encase the cable in a protective shield and secure the cable to prevent it from slipping.B. Periodically check the cable for kinks and wear. Replace the cable when necessary.C. Run the cable through the ceiling area instead of across the floor.D. Run the cable under the carpet.
Answer:
C
Explanation:
Prevents further damage to the network cable.
A balloon blown up with air hanging in a room. as the air in the room becomes colder the balloon becomes smaller because the molecules of air become?
.If a vehicle covers 3 km in 5 minutes, calculate the speed of the vehicle? (With process )
Answer:
Speed = 1.6 m/s
Explanation:
Formula,
Speed = Distance ÷ Time
Một vật chuyển động thẳng biến đổi đều đi hết quãng đường AB trong thời gian 6 giây. Vận tốc của vật khi đi qua điểm A là 5m/s, khi đi qua điểm B là 15m/s. Tìm chiều dài của quãng đường AB. A. 50 m B. 80 m C. 60 m D. 70 m →→→
Câu trả lời:
C. 60 m
Giải trình:
Cho rằng:
Tốc độ tại A, u = 5m / s
Tốc độ tại B, v = 15m / s
Độ dài quãng đường, AB =?
Tổng thời gian di chuyển = 6 giây
Hãy tính gia tốc, a:
a = (v - u) / t
a = (15 - 5) / 6
a = 1,667 m / s²
Từ :
v² = u² + 2aS
Trong đó, S = khoảng cách
15² = 5² + 2 (1.667 * S)
225 = 25 + 3,334S
225 - 25 = 3,334S
200 = 3,334S
S = 200 / 3,334
S = 59,98 m
S = 60 m
Car B is being pushed by a force of 22000 N. If it has a mass of 1375 kg.,
what is the acceleration of this car?
Answer:
a = 16 m/s²
General Formulas and Concepts:
Dynamics
Newton's Law of Motions
Newton's 1st Law of Motion: An object at rest remains at rest and an object in motion stays in motion Newton's 2nd Law of Motion: F = ma (Force is equal to [constant] mass times acceleration) Newton's 3rd Law of Motion: For every action, there is an equal and opposite reactionExplanation:
Step 1: Define
Identify variables
[Given] F = 22000 N
[Given] m = 1375 kg
[Solve] a
Step 2: Find Acceleration
Substitute in variables [Newton's 2nd Law of Motion]: 22000 N = (1375 kg)aIsolate a: 16 m/s² = aRewrite: a = 16 m/s²The weight of a girl on the Earth is 340 N, what is her mass on Earth?(g= 10Nkg-1)
Answer:
34 kg is the answer to the question
¿Cómo se presentan las cargas en la materia, en su estado natural y que no presentan campos eléctricos?
Answer: Se presentan en equilibrio a nivel atómico y/o molecular
Explanation: Sólo los iones presentan campo eléctrico pero no son estables en la naturaleza ya que tienden a encontrar al ion de carga opuesta con el cual equilibrar la carga. El estado de equilibrio de un cuerpo o materia se da al tener idéntica cantidad de electrones (-) que de protones (+)-
Aiden is writing a report about the structure of the atom. In her report, she says that the atom has three main parts and two subatomic particles. Do you agree with her? Why or why not?
Answer:
I don't agree
Explanation:
Atoms have 3 subatomic particles protons, electrons and neutrons,
Which of the following refers to friction that acts on an object that is not moving? O A. Kinetic friction O B. Inertia O c. Contact force O D. Static friction
HELP PLEASE!!
Answer:
D.STATIC FRICTION
Explanation:
Have a nice day
A small block is attached to a spring with a spring constant of 85 N/m. When the spring is compressed 0.30 meters and the released, the 0.50 kg block is launched. What is the final speed of the block?
A)
8.42 m/s
B)
3.91 m/s
C)
7.14 m/s
D)
15.3 m/s
Answer:
Explanation:
These Hooke's Law problems are tricky. Here's what we need to know that clears up the problem entirely. The final and also the max speed of the block will be reached at the point where the potential energy of the system is 0. So the equation we need, namely,
[tex]KE+PE=\frac{1}{2}kA^2[/tex] can be simplified down to
[tex]KE=\frac{1}{2}kA^2[/tex] and we solve this first for KE:
[tex]KE=\frac{1}{2}(85)(.30)^2[/tex] and, paying NO attention whatsoever to significant digits here (because if you did the answer you get is not one of the choices)
KE = 3.825 J. Now we can use that value of kinetic energy and solve for the speed we need:
[tex]KE=\frac{1}{2}mv^2[/tex] so
[tex]3.825=\frac{1}{2}(.50)v^2[/tex] so
[tex]v=\sqrt{\frac{2(3.825)}{.50} }[/tex] so
v = 3.91 m/s
Rewrite the false statements correctly
1.If an object sinks in one liquid and floats on another liquid,it implies that the density of second liquid is less than the first liquid.
2.The immersed volume of body in a liquid depends on density of the liquid.
3.Relative density of a body is usually expressed in kgm^-3
Explanation:
1. if an object sjnks in one liquid and floats on another liquid it implies that the density of second liquid is greater than the density of first liquid
what is importance of measurment in our daily life ?
Measurement tools improve the quality and quantity of our lives by making them easier and safer. The ability to precisely quantify physical qualities has arguably enormous survival value, providing humans with an adaptive, evolutionary advantage refined over thousands of years of natural selection.
#CarryOnLearning
Alcohol of mass 21g and density 0.7gcm-3 is mixed with 10g of water. Determine the density
of the mixture. (density of water = 1.0g cm-3)
Answer:
0.775 g/cm³
Explanation:
The given parameters are;
The mass of the alcohol = 21 g
The density of the of the alcohol = 0.7 g/cm³
The mass of water with whichit is mixed = 10 g
The density of water = 1.0 g/cm³
Therefore, the mass of the mixture, m = 21 g + 10 g = 31 g
Volume = Mass/Density
The volume of the alcohol = 21 g/(0.7 g/cm³) = 30 cm³
The volume of the water = 10 g/(1.0 g/cm³) = 10 cm³
Therefore, the volume of the mixture, V = 30 cm³ + 10 cm³ = 40 cm³
The density of the mixture, ρ = (Mass, m)/(Volume, V) = m/V
∴ ρ = (31 g)/(40 cm³) = 0.775 g/cm³
The density of the mixture, ρ = 0.775 g/cm³.
What is the difference between potential and kinetic types of energy? 1 pois
Answer:
Potential energy is energy that is stored in an object or system. It remains unaffected by the environment outside of the object or system. Kinetic energy is the energy of an object or a system's particles in motion.
Explanation:
I need help answer these questions please
Answer:
1. 25 J
2. 250 J
3. 900,000 J
4. 7,500 J
Explanation:
1. The distance the wheelbarrow is tilted, d = 0.5 m
The force used to tilt the wheelbarrow, F = 50 N
The work done, W = F × d
∴ W = 50 N × 0.5 m = 25 J
2. Work done, W = Force × Distance
The applied force, F = 50 N
The distance the sand is moved, d = 5 m
∴ W = 50 N × 5 m = 250 J
3. The work done, W = The load lifted × The height to which the load is lifted
∴ W = 90,000 N × 10 m = 900,000 J
The work done, W = 900,000 J
4. The work output of the skateboard = The work input × Efficiency
Given that the skateboard is an ideal machine, we have;
The work output of the skateboard = The work input = W
W = F × d
F = 15 N, d = 500 m
∴ W = 15 N × 500 m = 7,500 J
The work output of the skateboard = W = 7,500 J.
What is kinetic and potential energy?
Answer:
the energy produced in a body due to its motion is kinetic energy.
energy produced in a body due to its position is potential energy.
Explanation:
kinetic energy is the energy possessed by a body in motion
Potential energy is the energy possessed by a body by virtue of its position with respect to a reference level
A mobile phone is 35% efficient. Over half an hour 11 kJ of energy is transferred to the phone.
Calculate the amount of energy usefully transferred by the machine over half an hour.
[tex]\\ \sf\longmapsto 35\%\:of 11[/tex]
[tex]\\ \sf\longmapsto 35\%\times 11[/tex]
[tex]\\ \sf\longmapsto \dfrac{35}{100}\times 11[/tex]
[tex]\\ \sf\longmapsto \dfrac{385}{100}[/tex]
[tex]\\ \sf\longmapsto 3.85KJ[/tex]
[tex]\\ \sf\longmapsto 3850J[/tex]
Hitungkan pecutan bagi blok di bawah: / Cal
(a)
m= 2 kg
F= 8.0 N
Answer:
Acceleration = 4 m/s²
Explanation:
Given the following data;
Force = 8 N
Mass = 2 kg
To find the acceleration of the block;
Newton's Second Law of Motion states that the acceleration of a physical object is directly proportional to the net force acting on the physical object and inversely proportional to its mass.
Mathematically, it is given by the formula;
[tex] Acceleration = \frac {Net \; force}{mass} [/tex]
Substituting into the formula, we have;
[tex] Acceleration = \frac {8}{2} [/tex]
Acceleration = 4 m/s²
Which statement describes how chemical formulas, such as H20, represent compounds?
Answer:
They show the elements that make up a compound.
They show the three-dimensional shape of a molecule.
They show the types of atoms that make up a molecule.
They show the number of each type of atom in a molecule.
Explanation:
❣️(◍Jess bregoli◍)❣️#keep learning!!
the train left weston and arrived at easton 3 hours and 30 minutes later the speed was 104 km per hour what was the total distance covered?
Answer:
104 times by 3.3
Explanation:
104 is the distance for 1 hour. So you need to multiply it by 3.3( because it's 3 hour and 30 minutes)
A pole-vaulter first converts kinetic energy into
a. thermal energy.
b. chemical energy. mechanical energy.
c. mechanical energy
d. elastic potential energy.
Answer:
d. elastic potential energy
hey what is Krichoff rule
good morning
Explanation:
sorry I've got a bad hand writing but i think ull understand more with the screenshot that I've just pinned for u there
Answer:
this guy has answed ur question lol