Answer:
i = 4.9 A
Explanation:
The expression for the magnetic force in a wire carrying a current is
F = i L x B
bold letters indicate vectors.
The direction of the cable is towards the East, the direction of the magnetic field is towards the North, so the vector product is in the vertical direction (z-axis) upwards and the weight of the cable is vertical downwards. Let's apply the equilibrium condition
F - W = 0
i L B = m g
They indicate the linear density of the cable λ = 0.2 kg / m
λ = m / L
m = λ L
we substitute
i B = λ g
i = [tex]\frac{ \lambda \ g}{B}[/tex]
let's calculate
i = 0.2 9.8 / 0.4
i = 4.9 A
a net force of 5N is applied to a 13kg mass. what is its acceleration?
Answer:
[tex]\boxed {\boxed {\sf a \approx 0.4 \ m/s^2}}[/tex]
Explanation:
According to Newton's Second Law of Motion, force is the product of mass and acceleration.
[tex]F= m \times a[/tex]
The net force is 5 Newtons and the mass is 13 kilograms. Let's convert the units for force to make the problem and unit cancellation easier.
1 Newton (N) is equal to 1 kilogram meter per square second (1 kg*m/s²) The net force of 5 N is equal to 5 kg*m/s²Now we know the values for 2 variables:
F= 5 kg*m/s²m= 13 kgSubstitute the values into the formula.
[tex]5 \ kg *m/s^2 = 13 \ kg * a[/tex]
Since we are solving for the accleration we must isolate the variable, a. It is being multiplied by 13 kilograms and the inverse of multiplication is division. Divide both sides by 13 kg
[tex]\frac {5 \ kg *m/s^2}{13 \ kg}= \frac{ 13 \ kg *a}{13 \ kg}[/tex]
[tex]\frac {5 \ kg *m/s^2}{13 \ kg}=a[/tex]
The units of kilograms (kg) cancel.
[tex]\frac {5 m/s^2}{13 }=a[/tex]
[tex]0.384615385\ m/s^2=a[/tex]
The original measurements of force and mass ( 5 and 13) have 1 and 2 significant figures. We must round our answer to the least number of sig figs: 1.
For the number we found, that is the tenths place. The 8 in the hundredth place (0.384615385) tells us to round the 3 up to a 4.
[tex]0.4 \ m/s^2 \approx a[/tex]
The acceleration is approximately 0.4 meters per square second.
what is photoelectron
Answer:
The answer is:-
Explanation:
An electron emitted from an atom by enteraction with an photon, especially an eclectron emitted from a solid surface by the action of light.
A air glider of mass 1.0 kg that is equipped with a spring bumper travels at a speed of 2.5 m/s toward a second stationary glider of mass 0.75 kg. What is the final speed of the 0.75 kg cart
Answer:
the final speed of the 0.75 kg cart is 2.86 m/s
Explanation:
Given;
mass of the air glider, m₁ = 1.0 kg
initial speed of the air glider, u₁ = 2.5 m/s
mass of the stationary cart, m₂ = 0.75 kg
initial speed of the stationary cart, u₂ = 0
Let the final speed of the stationary cart = v₂
Also, let the final speed of the air glider = v₁
Since the air glider has a spring bumper, the collision will be elastic.
Apply the following principle of conservation of linear momentum for elastic collision.
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(1 x 2.5) + 0.75(0) = v₁ + 0.75v₂
2.5 = v₁ + 0.75v₂
v₁ = 2.5 - 0.75v₂ ----------- (1)
Apply one-dimensional velocity concept since the collision occured in one direction;
u₁ + v₁ = u₂ + v₂
2.5 + v₁ = 0 + v₂
v₁ = v₂ - 2.5 ----- (2)
solve (1) and (2) together;
v₂ - 2.5 = 2.5 - 0.75v₂
v₂ + 0.75v₂ = 2.5 + 2.5
1.75v₂ = 5
v₂ = 5 / 1.75
v₂ = 2.86 m/s
Therefore, the final speed of the 0.75 kg cart is 2.86 m/s
A model plane has a mass of 0.75 kg and is flying 12 m above the ground
with a speed of 18 m/s. What is the total mechanical energy of the plane?
The acceleration due to gravity is 9.8 m/s2.
Answer:
Option C. 210 J.
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 0.75 Kg
Height (h) = 12 m
Velocity (v) = 18 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Total Mechanical energy (ME) =?
Next, we shall determine the potential energy of the plane. This can be obtained as follow:
Mass (m) = 0.75 Kg
Height (h) = 12 m
Acceleration due to gravity (g) = 9.8 m/s²
Potential energy (PE) =?
PE = mgh
PE = 0.75 × 9.8 × 12
PE = 88.2 J
Next, we shall determine the kinetic energy of the plane. This can be obtained as follow:
Mass (m) = 0.75 Kg
Velocity (v) = 18 m/s
Kinetic energy (KE) =?
KE = ½mv²
KE = ½ × 0.75 × 18²
KE = ½ × 0.75 × 324
KE = 121.5 J
Finally, we shall determine the total mechanical energy of the plane. This can be obtained as follow:
Potential energy (PE) = 88.2 J
Kinetic energy (KE) = 121.5 J
Total Mechanical energy (ME) =?
ME = PE + KE
ME = 88.2 + 121.5
ME = 209.7 J
ME ≈ 210 J
Therefore, the total mechanical energy of the plane is 210 J.
Which of the following statements best describes energy conservation in heat engines?
A. The heat engine's energy is exhausted to the outside system.
B. The sum of the heat placed into the hot reservoir and the work collected equals the energy transferred from the cold reservoir.
C. A volume of heat is discharged to the cold body where some waste energy is in a form of heat in this engine.
D. The work derived from the heat engine is equal to the energy placed into the hot reservoir.
Consider two identical stars, A and B. Star B is 10 times farther away than star A. What is the difference in magnitudes between the two stars?
You can't tell. It depends on other things besides just their distance.
IF the stars are really really "identical", then the magnitude of Star-B is the number that is 6 more than the magnitude of Star-A.
Which of the following would NOT produce a current? A. Moving a bar magnet inside a coil of wire O B. Moving a bar magnet toward a straight wire C. Moving a straight wire toward a bar magnet O D. Placing a bar magnet next to a wire.
Answer:
c
Explanation:
Answer:C
Explanation:
An electric drill at 400 W is connected to 120 V power line. What is the resistance of the drill?
Answer:
36 ohm
Explanation:
Given :
P=400 W
V=120V
Now,
[tex]P=\frac{V^{2} }{R} \\400=\frac{120^{2} }{R} \\400R=14400\\R=\frac{14400}{400} \\R=36 ohm[/tex]
Therefore, resistance of the drill will be 36 ohm
During a circus act, an elderly performer thrills the crowd by catching a cannon ball shot at him. The cannon ball has a mass of 72.0 kg and its horizontal component of velocity is 6.50 m/s just before the 65.0 kg performer catches it. If the performer is initially motionless on nearly frictionless roller skates, what is his speed immediately after catching the cannon ball
Answer:
3.416 m/s
Explanation:
Given that:
mass of cannonball [tex]m_A[/tex] = 72.0 kg
mass of performer [tex]m_B[/tex] = 65.0 kg
The horizontal component of the ball initially [tex]\mu_{xA}[/tex] = 6.50 m/s
the final velocity of the combined system v = ????
By applying the linear momentum of conservation:
[tex]m_A \mu_{xA}+m_B \mu_{xB} = (m_A+m_B) v[/tex]
[tex]72.0 \ kg \times 6.50 \ m/s+65.0 \ kg \times 0 = (72.0 \ kg+65.0 \ kg) v[/tex]
[tex]468 kg m/s + 0 = (137 kg)v[/tex]
[tex]v = \dfrac{468\ kg m/s }{137 \ kg}[/tex]
v = 3.416 m/s
Phosphorus (P) is an element with an atomic number of 15 and an atomic mass of 31. How many neutrons are in an atom of phosphorus? A.15 B.16 C.31 D.46
(31-15 = 16).
Explanation:
the element phosphorus (P) has an atomic number of 15 and a mass number of 31. Therefore, an atom of phosphorus has 15 protons, 15 electrons, and 16 neutrons
Phosphorus (P) is an element with an atomic number of 15 and an atomic mass of 31, there are 16 neutrons in an atom of phosphorus, therefore the correct answer is option B
What is the atomic number?The total number of protons present in an atom is known as the atomic number of that atom. The atomic number has no correlation either with the number of neutrons or the number of electrons present inside an atom.
As given in the problem Phosphorus (P) is an element with an atomic number of 15 and an atomic mass of 31
Total number of proton in phosphorus = 15
Total number of neutrons in the phosphorus = atomic mass - atomic number
Total number of neutrons in the phosphorus =31 -15
Total number of neutrons in the phosphorus = 16
Thus, the total number of neutrons in a phosphorus atom would be 16, therefore the correct answer is option B
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What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 555 nmnm
Answer:
The minimum thickness of soap film is [tex]2.086\times 10^{-7} m[/tex].
Explanation:
wavelength = 555 nm
refractive index, n = 1.33
For the destructive interference,
the thickness is given by
[tex]t =\frac{m \lambda }{2 n}[/tex]
Here, m is the order, n is the refractive index and [tex]\lambda[/tex] is the wavelength.
For minimum thickness, m = 1
So the thickness is
[tex]t =\frac{1 \times 555\times 10^{-9} }{2 \times 1.33}\\\\t = 2.086\times 10^{-7} m[/tex]
150 0.0000
2. Use the distance from the previous problem to calculate how long it takes for light to travel from the
Sun to Earth.
300,000,000X 15000,000,
Answer:
t = 5 10² s
Explanation:
Light is an electromagnetic wave that travels at a constant speed of 3 10⁸ m/s in vacuum.
The distance from the Sun to the Earth is 150 10⁶ km
Let's reduce the distance to the SI system
x = 150 10⁶ km (10³ m / 1 km) = 150 10⁹ m
Since the velocity is constant, we can use the uniform motion relations
v = x / t
t = x / v
let's calculate
t = 150 10⁹ / 3 10⁸
t = 5 10² s
what is parallelogram law of vector addition ???
Answer:
According to the parallelogram law of vector addition if two vectors act along two adjacent sides of a parallelogram(having magnitude equal to the length of the sides) both pointing away from the common vertex, then the resultant is represented by the diagonal of the parallelogram passing through the same common vertex
Explanation:
Subtract the following numbers, using scientific notation and the correct number of significant digits.
6.94 × 103 mm - 4.5 × 102 mm = _____.
2.4 × 103 mm
2.44 × 102mm
6.49 × 103 mm
6.5 × 103 mm
Answer:
The correct answer is - 6.49 × 10^3 mm.
Explanation:
The correct scientific notation of the given subtraction problem is:
6.94 × 10^3 mm - 4.5 × 10^2 mm = _____.
The correct number of significant digits is
a. 6.94 × 10^3 mm = 3
b. 4.5 × 10^2 mm = 2
So subtracting the 6.94 × 10^3 mm - 4.5 × 10^2 mm
= 6940 - 450
= 6.49× 10^3 mm.
Answer:
6.5x 10^3 mm
Explanation:
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 ?
A violinist is tuning her violin to 440Hz. She plays the note while listening to an electronically generated tone and hears 3Hz, which increases to 4Hz when she tightens the violin. What was the frequency of the note played by the violin when she heard the 3 Hz beats
Answer:
[tex]X=438Hz[/tex]
Explanation:
From the question we are told that:
Beat Frequency [tex]Fb=440Hz[/tex]
Actual Frequency [tex]F_a=3Hz[/tex]
Generally the equation for Frequency Heard X is mathematically given by
[tex]X=beat\ frequency\ +\ actual\ frequency[/tex]
[tex]X=F_a+Fb[/tex]
[tex]X= 440Hz+3Hz[/tex]
[tex]X=438Hz[/tex]
Find the acceleration due to gravity on the surface of a planet with a mass of 3.5 * 10^24 kg and an average radius of 4.5 * 10^6 m.
Explanation:
.........
.....
.......
A package of mass m is released from rest at a warehouse loading dock and slides down a 3.0-m-high frictionless chute to a waiting truck. Unfortunately, the truck driver went on a break without having removed the previous package, of mass 2m, from the bottom of the chute. Suppose the packages stick together. What is their common speed after the collision
Answer:
The speed of combined package after the collision is [tex]\frac{\sqrt(2gh)}{4}\\[/tex].
Explanation:
mass of first package = m
height , h = 3 m
mass of second package = 3 m
let the speed of first package is u as it strikes with the second package.
Use the third equation of motion
[tex]v^2 = u^2 + 2 gh \\\\u^2 = 0 + 2 g h \\\\u = \sqrt {2gh}[/tex]
Let the velocity of combined package after the collision is v.
Use the conservation of momentum
[tex]m\times u + 3m \times 0= (m + 3m)\times v\\\\m u = 4mv \\\\v=\frac {u}{4}\\\\v = \frac{\sqrt(2gh)}{4}\\\\[/tex]
Constants Periodic Table Part A Carla holds a ball 1.5 m above the ground. Daniel, leaning out of a car window, also holds a ball 1.5 mm above the ground. Daniel drives past Carla at 40 mph and, just as he passes her, both release their balls at the same instant.
Whose ball hits the ground first?
The balls will hit the ground simultaneously.
Daniel's.
Carla's The answer can't be determined from the data provided
Answer:
correct answer is c
The balls will hit the ground simultaneously
Explanation:
This is an exercise in kinematics, let's analyze each case separately
Carla. Holds the ball at an initial height y = 1,5m and releases the ball therefore its initial velocity is zero v₀ = 0
y = y₀ + v₀ t - ½ gt²
0 = y₀ + 0 - ½ g t²
t = [tex]\sqrt{\frac{2y_o}{g} }[/tex]
Daniel This holds the ball at I = 1.5 m and releases the ball as it passes by Carla, therefore the initial velocity is
horizontal vox = 40 mph
vertical v_{oy} = 0
y = y_{oy}I + v_{oy} t - ½ g t²
0 = y_{oy} + 0 - ½ g t²
t = [tex]\sqrt{\frac{2 y_o}{g} }[/tex]
we can see that they both spend the same time reaching the ground
t = [tex]\sqrt{2 \ 1.5 / 9.8}[/tex]
t = 0.55 s
The correct answer is c
The balls will hit the ground simultaneously
What is the reaction force when baseball catcher catches and stops a baseball?
When the baseball catcher catches a baseball, then ... during the time that he is slowing the ball down and stopping it ... he is exerting an action force with his glove on the ball, and the ball is exerting an equal and opposite reaction force on his glove.
1. What is the difference between longitudinal and transverse waves? Compare and contrast the direction of their movement, movement of a molecule through the completion of a cycle, and amplitude and wavelength measurements of each type of wave.
2. Suppose that a wave has a period of 0.03 second. What’s its frequency? Be sure to show the steps for your work.
3. Compare a wave that has a period of 0.03 second with a second wave that has a period of 1/4 second. Which wave has the greater frequency? Be sure to show the steps for your work.
4. If a wave has wavelength of 4.5 meters and a period of 0.07 second, what’s the velocity of the wave? Be sure to show the steps of your work.
5. Using the image below, identify the numbered parts of the wave.
Answer:
Explanation:
1. The waves in which the partciles of medium vibrates in the same direction of propagation of wave, are called longitudinal waves.
The waves in which the partciles of medium vibrates in the perpendicular direction of propagation of wave, are called transverse waves.
2. Period, T = 0.03 s
The frequency is given by the reciprocal of the period.
[tex]f=\frac{1}{T}\\\\f =\frac{1}{0.03}\\\\f = 33.3 Hz[/tex]
1. Transverse waves carry molecules at right angles to the direction in which the wave travels. Within a cycle, molecules move from their normal position to the highest position, back through the normal position to the lowest point, and then back to the normal position. The molecules retain their horizontal positions while vibrating vertically. Amplitude is measured at right angles to the direction of the travel of the wave. Wavelength can be represented as the distance between any two molecules in phase with each other, such as the two nearest molecules at the crests of the wave.
Longitudinal waves carry molecules parallel to the direction in which the wave travels. Within a cycle, a molecule travels in the same direction as the wave (from normal position to its most distant point on one side of its normal position), changes direction, moves back through its normal position to the opposite side of its normal position at a point that corresponds, and then returns to its normal position. The molecules don’t all move at the same time; some remain stationary as others go through a vibrating motion. Compressions and rarefactions occur here. Amplitude is measured parallel to the direction of the wave. Wavelength may be represented as the distance between the two nearest molecules that didn’t vibrate, the two nearest molecules at maximum compression, or the two nearest molecules at maximum rarefaction.
2. f = 1⁄T
f = 1⁄0.03
f = 33. 3 Hz
3. The first wave has a frequency of 33.3 Hz:
f1 = 1⁄T1
f1 = 1⁄0.03
f1 = 33. 3 Hz
The second wave has a frequency of 4 Hz. f2 = 1⁄T2
f2 = 1⁄1⁄4
f2 = 1 ÷ 1⁄4
f2 = 1 × 4⁄1
f2 = 1⁄1 × 4⁄1
f2 = 4 Hz
Therefore, the first wave has a higher frequency.
4. v = I⁄T
v= 4.5⁄0.007
v = 642.9 m/s
5. Wavelength
Crest
Trough
Amplitude
FORCE AND DISPLACEMENT AT AN ANGLE A sailor pulls a boat a distance of 30.0 m along a dock using a rope that makes a 25.0° angle with the horizontal. How much work does the rope do on the boat if its tension is 255 N?
Answer: 6117.58 J
Explanation:
We know that W=Fd*cos(theta) where theta is the angle between the displacement and the force.
In this case, we are given that F=225 N, d=30 m, and theta=25 degrees.
Plugging all this in we get
W=225*30*cos(25)=6117.58 J
Work done by the rope when sailor pulls the boat in the dock is 6930.9 J
What is work ?The work is defined by the product of force and displacement. Its standard formula is,
[tex]W = F.d.Cos\alpha[/tex]
Here F is force, d is displacement and α is angle subtended by force from horizontal.
As given in the question,F = 255N, d = 30m, α = 30°
On putting in the above formulaW = 255×30×Cos30°
=7650×0.906
= 6930.9 J
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4.Upthrust doesnt depend on the following Physical quantity?
volume of body
density of body
mass of body
acceleration due to gravity
Answer:
C: Mass of body
Explanation:
Upthrust is defined as the upward force that a liquid will exert on a body floating atop it.
Now, Formula for upthrust is;
Upthrust = density of liquid × volume of the body × acceleration due to gravity.
From the formula, we can see that upthrust depends on density, volume and acceleration due to gravity.
Thus, looking at the options, the one that doesn't apply is mass of body.
What is the kinetic energy of a 10kg object moving at 2.0m/s? *
Answer:
20J
Explanation:
[tex]KE = \frac{1}{2} mv^{2} = \frac{1}{2} (10)(2)^{2} =20J[/tex]
What is the average speed (in km/h) of Zhana, who runs to the store that is 4.0 km away in 30.0 minutes?
0.13 km/ h
8.0 km/h
2.0 km/h
Answer:
2.0km/h.
Explanation:
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With the frequency set at the mid-point of the slider and the amplitude set at the mid-point of the slider, approximately how many grid marks is the wavelength of the wave (use the pause button and step button as you need to in order to get a good measure, and round to the nearest whole grid mark)?
If the amplitude is increased the wavelength:___________.
a. decreases
b. stays the same
c. increases
Answer:
correct answer is b
Explanation:
The frequency of a wave depends on the properties of medium density and the elasticity properties change the amplitude depends on the energy carried by the wave, that is, the amplitude is proportional to the height of the wave (oscillation).
Consequently the amplitude of independent of the frequency because it depends on different factors.
Therefore when changing the amplitude the wavelength remains constant
the correct answer is b
A stretched rubber band is an example of which type potential energy
Answer: elastic potential energy
Explanation:
Answer:
Elastic potential energyExplanation:
A stretched rubber band has the potential to do work or change things. This form of energy is called elastic potential energy.
❣️✧Jess bregoli ✧❣️#keep learning!!It is important to use the correct drying tempture because it prevents shrinkage and will not damage the garment.
True or False
Answer:
fjowe
Explanation:
kbegtrf3g4ef j3kq4ef 3w4beysrf2w4er8f6ywgbaebf7v2wy4egdwa4i6e5
What are vectors and Scalar?
Answer:
vectors are the quantities that are described by both magnitude and direction
scalar are the quantities that are described by magnitude only
I hope it helps
Answer:
scalar : just magnitude
vector : magnitude and direction
Explanation:
Scalar And Vector. ... A scalar quantity is defined as the physical quantity that has only magnitude, for example, mass and electric charge. On the other hand, a vector quantity is defined as the physical quantity that has both magnitude as well as direction like force and weight.
What is the rate at which distance changes called
Answer:
a yard
Explanation: