Answer:
1. The best definition of refraction is ____.
a. passing through a boundary
b. bouncing off a boundary
c. changing speed at a boundary
d. changing direction when crossing a boundary
Answer: D
Bouncing off a boundary (choice b) is reflection. Refraction involves passing through a boundary (choice a) and changing speed (choice c); however, a light ray can exhibit both of these behaviors without undergoing refraction (for instance, if it approaches the boundary along the normal). Refraction of light must involve a change in direction; the path must be altered at the boundary.
a bell rings at a frequency of 75hz on a warm 25 degree evening. calculate the...
a. speed of the sound wave at this temperature.
b. wavelength of the sound wave
Answer:
Explanation:
We need 2 different equations for this problem: first the velocity of sound equation, then the frequency of the sound equation.
The velocity of sound is found in:
v = 331.5 + .606T
We need to find that first in order to fill it into the frequency equation which is
[tex]f=\frac{v}{\lambda}[/tex] where v is the velocity we will find the part a, f is frequency and lambda is the wavelength. Starting with the velocity of the sound:
v = 331.5 + .606(25) and
v = 331.5 + 15 and rounding correctly using the rules for sig fig when adding:
v = 347 m/s
Filling that into the frequency equation:
[tex]75=\frac{347}{\lambda}[/tex] and
[tex]\lambda=\frac{347}{75}[/tex] so
[tex]\lambda=4.6m[/tex]
Một dây dẫn mảnh được uốn thành một cung tròn bán kính 10cm, góc ở tâm bằng 1200, đặt trong không khí. Trong dây dẫn có dòng điện cường độ 30A chạy qua. Độ lớn của cảm ứng từ tại tâm của cung tròn là bao nhiêu ?
Answer:
Diana and that
Explanation:
muyayyano
Question 3
When a police officer is trying to decide if a driver is speeding, what is his point of reference?
The ground
His car
The speed limit
All of these
Đặt vào đầu hai dây dẫn cùng một hiệu điện thế bằng nhau U,có điện trở lần lượt là R1 và R2.Ta thấy cường độ dòng điện qua dây dẫn thứ nhất I1 lớn gấp hai lần cường độ dòng điện qua dây dẫn thứ hai I2
Answer:
The resistance ratio of first conductor to the second conductor is 1 : 2.
Explanation:
Current in first conductor = I1
Current in second conductor = I2 , I1 = 2 I2
According to the Ohm's law
[tex]V= I_1R_1..... (1)\\V = I_2 R_2 .... (2)\\[/tex]
From (1) and (2)
[tex]I_1 R_1 = I_2 R_2\\\\2I_2 R_1 = I_2 R_2\\\\2 R_1 = R_2[/tex]
PLease answer this question or explain
Which of the following stakeholders (who) expressed concern over the removal of the Bloede dam?
A Park Ranger
B Historian
C NOAA Scientist
Answer:
NOAA Scienctist
Explanation:
The stakeholder who expressed concern over the removal of the Bloede dam was the NOAA Scientist. So, option C.
What is meant by stakeholders ?A stakeholder is a person, group, or organization that has a vested interest in the choices made and the actions taken by a company, organization, or business initiative.
Here,
Stakeholders are important because, there wouldn't be any projects without them. The project can gain a lot from including its stakeholders.
They can participate in the decision-making process and have an impact on the organization's actions in a way that benefits the project management team.
The dismantling of Bloede Dam was long overdue given the environmental and safety concerns.
The difficulties caused by Bloede Dam are not unusual. Our nation's dams are increasingly hazardous to the environment and dangerous to people, with more than 90,000 dams blocking rivers around the country, including at least 659 in Maryland alone.
Hence,
The stakeholder who expressed concern over the removal of the Bloede dam was the NOAA Scientist. So, option C.
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when two capacitors are connected in series, the effective capacitance is 2.4muF and when connected in parallel, the effective capacitance is 10muF. calculate the individual capacitances.
Answer:
let one capacitor be x and other be y
[tex]in \: parallel \: connection : \\ \frac{x + y}{xy} = 10 \times {10}^{ - 6} - - - (a) \\ in \: series \: connection : \\ x + y = 2.4 \times {10}^{ - 6} - - - (b) \\ in \: (a) : \\ \frac{2.4 \times {10}^{ - 6} }{xy} = 10 \times {10}^{ - 6} \\ xy = 0.24 - - - (c) \\ from \: (b) : \\ y = (2.4 \times {10}^{ - 6} ) - x \\ \therefore \: in \: (c) : \\ x(2.4 \times {10}^{ - 6} - x) = 0.24 \\ 2.4 \times {10}^{ - 6} x - {x}^{2} = 0.24 \\ {x}^{2} - 2.4 \times {10}^{ - 6} x - 0.24 = 0 \\ x = 0.5 \\ 0.5y = 0.24 \\ y = 0.48 \\ { \boxed{ C _{1} = 0.5 \: farads}} \\ { \boxed{C _{2} = 0.48 \: farads}}[/tex]
Which law is stated below?
All forces exist in action-reaction pairs.
A. Newton's third law
B. Newton's first law
C. Newton's second law
D. The law of inertia
Answer:
Maybe the answer is Newton's third law
You plan to use a slingshot to launch a ball that has a mass of 0.019 kg. You want the ball to accelerate straight toward your target at 23 m/s2. How much force do you need to apply to the ball?
Answer:
Explanation:
this is a simple application of Newton's 2nd Law: F = ma.
F = .019(23) so
F = .44 N
You would need to apply a force of 0.437 Newtons to the ball in order to achieve the desired acceleration of 23 m/s².
Force is a physical quantity that describes the interaction between objects or systems and their ability to change motion or shape. It is a vector quantity, meaning it has both magnitude and direction. Force can cause an object to accelerate, decelerate, or change direction.
According to Newton's second law of motion, force is directly proportional to the mass of an object and the acceleration it experiences. The equation F = m × a represents this relationship, where F is the force, m is the mass of the object, and a is the acceleration.
Force can be measured in various units, such as Newtons (N) in the International System of Units (SI) or pounds (lb) in the US customary system. Common examples of forces include gravity, friction, tension, compression, and applied forces like pushing or pulling an object.
According to Newton's second law of motion, which states that force (F) is equal to mass (m) multiplied by acceleration (a):
F = m × a
In this case, the mass of the ball is given as 0.019 kg, and the desired acceleration is 23 m/s². Plugging these values into the equation, we can calculate the force:
F = 0.019 kg × 23 m/s²
F = 0.437 kg m/s²
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Bones are composed of three main components, what are they? (Choose all that apply)
Answer:
funny bone and compact bone
Explanation:
your funny bone only reacts if you hit it against something the compact bone is the heaviest and strongest bone in your body and the bone marrow is soft sponge like tissue in the center if most bones that produces white and red blood cells
If the distance between the source of sound and observer is reduced to one half, then
the intensity of sound will become
Answer:
Let the power delivered by the sound wave be 'P'
Intensity by definition is the power delivered per unit area.
i.e. I =
dA
dP
;
In spherical polar coordinate system dA = r
2
Ω
I =
r
2
Ω
dP
;
I ∝
r
2
1
So if distance increases 3 fold. The Intensity becomes
9
1
times the initial
If a 5.0Ω resistor, a 9.0Ω resistor, and a 13.0Ω resistor are connected in series with a 24.0 V battery, calculate the total resistance.
0.037Ω
0.89Ω
585Ω
27.0Ω
Answer: 27Ω
Explanation:
Quando o circuito está em série, a resistência total é igual ao somatório das resistências parciais do circuito.
the use of thermostat in a gas cooker is to
Explanation:
An oven thermostat regulates the temperature inside an oven. The thermostat's temperature-sensitive probe measures the oven's warmth, switching the heat on and off as necessary to maintain the correct temperature.
The process of recovering valuable or useful materials from waste or scrap is called
a.
recycling.
c.
rebuilding.
b.
renewing.
d.
reducing.
Please select the best answer from the choices provided
A
B
C
D
Answer:
hi
Explanation:
what is energy?what its si unit
Answer:
energy is the capacity or ability to do work
its si unit is joule
What is the force between two charged objects called ?
Answer:
Coulomb force
Explanation:
The electric force between charged bodies at rest is conventionally called electrostatic force or Coulomb force. The force is along the straight line joining the two charges.
i will mark brainliest if you get it right.
Answer:
Satellite D
Explanation:
It has more mass
Felipe drives his car at a velocity of 28 m/s. He applies the brake, which slows the vehicle down at a rate of 6.4 m/s2 and causes it to slow to a stop. How long does it take for the car to stop? Round your answer to the nearest tenth.
Answer:
Explanation:
Use the one-dimensional equation
[tex]v_f=v_0+at[/tex] where v is the final velocity, v0 is the initial velocity, a is the acceleration, and t is the time it takes to reach that final velocity. We are solving for t. Filling in the other values:
0 = 28 + (-6.4)t and
-28 = -6.4t so
t = 4.4 seconds
Answer:
4.4
Explanation:
How do you complete this mixed circuit?
For the resistor closest to the battery, drawn vertical in the diagram, I = 8 A and P = 320 watts.
Also, the battery voltage is 40 V.
There isn't enough information included in the picture to fill in any of the missing items for the other two resistors.
what revovles around the sun and is made out of rock,ice,gas,and dust?
Answer:
Comets are cosmic snowballs of frozen gases, rock and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet's orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets.Hope this is fine for you,,!!А______
is a unit of measurement for energy. (7 Letters)
Answer:
Joule or kilowatt/hour
which factor is least likely to limit the rate of photosynthesis?
- carbon dioxide concentration
- light intensity
- oxygen concentration
- temperature
Answer:
oxygen concentration
Explanation:
A 2kg mass and a 4kg mass on a horizontal frictionless surface are connected by a massless string A. They are pulled horizontally across the surface by a second string B with a constant acceleration of 12 m/s^2. What is the magnitude of the force of string B on the 2kg mass?
Answer:
72 N
Explanation:
Applying,
F = (m'+m)a..................... Equation 1
Where F = Force, m' = First mass, m = second mass, a = acceleration.
From the question,
m' = 2 kg, m = 4 kg, a = 12 m/s²
Substitute these values into equation 1
F = 12(2+4)
F = 12×6
F = 72 N
Which variable is represented by the following symbol? ∑F
a. Normal Force
b. Applied Force
c. Weight
d. Net Force
The temperature of an ideal gas in a sealed 0.40m3 rigid container is reduced from 350 K to 270 K.The final pressure of the gas is 60 kPa. The molar heat capacity at constant volume of the gas is 28.0 J/(mol K). The heat absorbed by the gas is closest to
Answer:
The answer is below
Explanation:
Given that the volume (V) = 0.4 m³, temperature difference (ΔT) = 270 K - 350 K = -80 K, pressure (P) = 60 kPa = 60000 Pa, R = 8.314 J/molK
Since we have constant volume, we can use the final state parameters to calculate the number of moles using the ideal gas law:
[tex]PV=nRT\\\\n=\frac{PV}{RT} =\frac{60000*0.4}{8.314*270} =10.69\ moles[/tex]
Given that the molar heat capacity at constant volume ([tex]C_v[/tex]) = 28.0 J/(mol K), the heat absorbed (Q) is:
[tex]Q=nC_v\Delta T=10.69*28*(-80) = -23945.6\ J\\\\Q=-23.95\ kJ[/tex]
Q ≈ -24 kJ
Felipe drives his car at a velocity of 28 m/s. He applies the brake, which slows the vehicle down at a rate of 6.4 m/s2 and causes it to slow to a stop. How long does it take for the car to stop? Round your answer to the nearest tenth.
Answer:
4.4 seconds
Explanation:
use the equation
v(final)=v(initial)+a(t)
what we know:
v(initial)=28mps
v(final)=0 because it comes to a stop
a= -6.4 it is negative because the 6.4 is resisting forward motion
using these you get
0= 28 + (-6.4)t
6.4(t)=28
t=4.375 sec
and with rounding
t=4.4 sec
Answer:
4.4
Explanation:
i got it correct
A force of 30.0 N is applied to a 3.00 kg object for 3.00 seconds. Calculate the velocity experienced by the object.
Answer:
Explanation:
F = ma and
[tex]a=\frac{v}{t}[/tex]
We have F, we have m, but in order to solve for v, we need a.
30.0 = 3.00a so
a = 10.0 m/s/s. Plug that in for a in the second equation and solve for v:
[tex]10.0=\frac{v}{3.00}[/tex] so
v = 10.0(3.00) so
v = 30.0 m/s
A skier of weight 700 N is pointed down a ski hill that has a slope angle of 25° above horizontal.
What is the component of his weight pulling him down the slope.
O 634N
O 326N
O 296N
O 700N
Answer:
O 296N
Explanation:
F_y = F*sin(x)
F_y = 700N*sin(25°)
F_y = 295.83N or 296N
A gymnast with mass 50kg suspends herself from lower end of a hanging rope, upper end of the rope is attached to the ceiling. What is the weight of gymnast? Which of the Newton’s law related to your calculation? if gymnast fall with an acceleration of 2m/s2 , what is the force on the rope?
Answer:
I. Weight = 490 Newton
II. Newton's Second Law of Motion
III. Force = 100 Newton
Explanation:
Given the following data;
Mass = 50 kg
Acceleration = 2 m/s²
I. To find the weight of the gymnast;
Weight = mass * acceleration due to gravity
We know that acceleration due to gravity is equal to 9.8 m/s².
Weight = 50 * 9.8
Weight = 490 Newton
II. 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;
Force = mass * acceleration
[tex] F = ma[/tex]
III. To find the force, we would use the following formula;
[tex] F = ma [/tex]
[tex] F = 50 * 2[/tex]
Force = 100 Newton
In April 1974, Steve Prefontaine completed a 10.0 km race in a time of 27 min , 43.6 s . Suppose "Pre" was at the 7.71 km mark at a time of 25.0 min . If he accelerated for 60 s and then maintained his increased speed for the remainder of the race, calculate his acceleration over the 60 s interval. Assume his instantaneous speed at the 7.71 km mark was the same as his overall average speed up to that time.
Answer:
0.18 m/s²
Explanation:
The total time taken to cover a 10 km race is 27 min, 43.6 seconds.
At 25 min, Pre was at 7.71 km mark. Therefore the average speed = 7.71 km / 25 min = 7710 m / (25 * 60) s = 5.14 m/s
The distance remaining = 10 km - 7.71 km = 2.29 km = 2290 m
The remaining time = 27 min, 43.6 seconds - 25 min = 2 min 43.6 second = 163.6 seconds
She accelerates for 60 seconds, therefore the distance covered (S) during the acceleration (a) is:
S₁ = 5.14(60) + 0.5a(60)² = 308.4 + 1800a
She maintains the speed for the remaining distance (S₂). The remaining time = 163.6 seconds - 60 seconds = 103.6 seconds. The final speed after the acceleration = (5.14 + 60a) m/s
S₂ = (5.14 + 60a)* 103.6 = 532.5 + 6216a
S₁ + S₂ = 2290 m
(308.4 + 1800a) + (532.5 + 6216a) = 2290
8016a + 840.9 = 2290
8016a = 1449.1
a = 0.18 m/s²
what are scalar quantities and list their examples
Explanation:
these are quantities that have magnitude but no direction
Examples include : speed, mass, volume, density, everything, time