Answer:
A. Pull together
Explanation:
This is because the two magnets are unlike-poles so they attract to eachother
If riding a lawnmower engine exerts 19 hp in one minute to move the lawnmower how much work is done
Answer:
the work done by the lawnmower is 236.14 J.
Explanation:
Given;
power exerted by the lawnmower engine, P = 19 hp
time in which the power was exerted, t = 1 minute = 60 s.
1 hp = 745.7 watts
The work done by the lawnmower is calculated as follows;
[tex]Work = Energy = \frac{Power}{time} \\\\Work = \frac{(19 \times 745.7)}{60} = 236.14 \ J[/tex]
Therefore, the work done by the lawnmower is 236.14 J.
An electromagnetic wave with frequency 65.0Hz travels in an insulating magnetic material that has dielectric constant 3.64 and relative permeability 5.18 at this frequency. The electric field has amplitude 7.20×10−3V/m. What is the wavelength of the wave?
Answer:
The wavelength of the wave is [tex]1.06\times10^6 m[/tex]
Explanation:
Lets calculate
We know an electromagnetic wave is propagating through an insulating magnetic material of dielectric constant K and relative permeability [tex]K_m[/tex] ,then the speed of the wave in this dielectric medium is [tex]\nu[/tex] is less than the speed of the light c and is given by a relation
[tex]\nu=\frac{c}{\sqrt{KK_m} }[/tex] --------- 1
In case the electromagnetic wave propagating through the insulating magnetic material , the amplitudes of electric and magnetic fields are related as -
[tex]E_m_a_x= \nu B_m_a_x[/tex]
The magnitude of the 'time averaged value' of the pointing vector is called the intensity of the wave and is given by a relation
[tex]I = S_a_v[/tex]
[tex]\frac{E_m_a_xB_m_a_x}{2K_m\mu0}[/tex]----------- 3
now , we will find the speed of the propagation of an electromagnetic wave by using equation 1
[tex]\nu=\frac{c}{\sqrt{KK_m} }[/tex]
Putting the values ,
=[tex]\nu= \frac{3.00\times10^8}{\sqrt{(3.64)(5.18)} }[/tex]
=[tex]0.6908\times10^8m/s[/tex]
= [tex]6.91\times10^7m/s[/tex]
Now , using this above solution , we will find the wavelength of the wave -
[tex]\lambda=\frac{\nu}{f}[/tex]
Putting the values from above equations -
[tex]\frac{6.91\times10^7m/s}{65.0Hz}[/tex]
[tex]\lambda= 1.06\times10^6 m[/tex]
Hence , the answer is [tex]\lambda= 1.06\times10^6 m[/tex]
Determine the separation distance between two balloons with charges of +3.6*10^-8 C and -3.2*10^-8 C. They generate an electrical force of -2.2*10^-2 between them.
Answer:
0.0217 m
Explanation:
Ftom the question,
Applying Coulomb's law
F = kqq'/r²............... Equation 1
Where F = Electric Force, q and q' = First and second charge respectively, r = distance between the charges, k = coulomb's constant.
make r the subeject of the equation
r = √[(kqq')/F]............. Equation 2
Given: q = +3.6×10⁻⁸ C, q' = -3.2×10⁻⁸ C, F = -2.2×10⁻² N
Constant: k = 8.98×10⁹ Nm²/C²
Substitute these values into equation
r = √(+3.6×10⁻⁸×-3.2×10⁻⁸×8.98×10⁹/-2.2×10⁻²)
r = √(-103.4489×10⁻⁷/-2.2×10⁻²)
r = √(47.02×10⁻⁵)
r = 21.68×10⁻³
r ≈ 21.7×10⁻³ m.
r ≈ 0.0217 m
Hence the seperation between the two balloons is 0.0217 m
how can isotopes of a given element be identified?
Answer: All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom. ... Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons.
Explanation: Hopefully this helps. Have a great day.
Which of the following describes half-life? Choose which apply.
A. Half-life is the amount of time it takes for half of a sample to decay.
B. The shorter the half-life, the more unstable the nuclide.
C. Half-life cannot be calculated for nuclides.
D. The longer the half-life, the more stable the nuclide
please answer correctly
a body is moving with uniform acceleration, has initial velocity 45km/hr. and acceleration 20cm/s^2. find its velocity after 25 seconds
QUESTION 3
A 10 kg cement block is pulled across the floor with a force of 50 N at an angle of 30° with the
horizontal The block accelerates at 1,5 m s?
30°
10 kg
(2)
31
Define the term normal force
3.2
Draw a FORCE DIAGRAM showing ALL the forces acting on the object.
3.3
Calculate the magnitude of the
(3)
3.3.1 Normal force
(5)
3.3.2 Frictional force which acts on the crate
(4)
3.3.3 Coefficient of kinetic friction
[18]
fruittttstcwvwvw s https://media.tenor.co/imag
︶
Question 16 (1 point)
Light travels through a material at a speed of 4.3 x 108 m/s. What is the index of
refraction for the material?
Your Answer:
Answer
units
Answer:
η = 0.7
Explanation:
The refractive index of the material can be calculated by using the following formula:
[tex]\eta = \frac{c}{v}\\[/tex]
where,
η = refractive index of the material = ?
c = speedof light in vaccuum = 3 x 10⁸ m/s
v = speed of light in this material = 4.3 x 10⁸ m/s
Therefore,
[tex]\eta = \frac{3\ x\ 10^8\ m/s}{4.3\ x\ 10^8\ m/s}[/tex]
η = 0.7
An airplane traveling 919 m above the ocean at 505 m/s is to drop a case of twinkies to the victims below. How much time before being directly overhead should the box be dropped? What is the horizontal distance between the plane and the victims when the box is dropped?
Answer:
a. 13.7 s b. 6913.5 m
Explanation:
a. How much time before being directly overhead should the box be dropped?
Since the box falls under gravity we use the equation
y = ut - 1/2gt² where y = height of plane above ocean = 919 m, u = initial vertical velocity of airplane = 0 m/s, g = acceleration due to gravity = -9.8 m/s² and t = time it takes the airplane to be directly overhead.
So,
y = ut - 1/2gt²
y = 0 × t - 1/2gt²
y = 0 - 1/2gt²
y = - 1/2gt²
t² = -2y/g
t = √(-2y/g)
So, t = √(-2 × 919 m/-9.8 m/s²)
t = √(-1838 m/-9.8 m/s²)
t = √(187.551 m²/s²)
t = 13.69 s
t ≅ 13.7 s
So, the box should be dropped 13.69 s before being directly overhead.
b. What is the horizontal distance between the plane and the victims when the box is dropped?
The horizontal distance x between plane and victims, x = speed of plane × time it takes for box to drop = 505 m/s × 13.69 s = 6913.45 m ≅ 6913.5 m
define 1 unit electricity
Answer:
A unit is represented in kWH or Kilowatt Hour. This is the actual electricity or energy used. If you use 1000 Watts or 1 Kilowatt of power for 1 hour then you consume 1 unit or 1 Kilowatt-Hour (kWh) of electricity.
In context of nepal it is better to use energy like solar power .why?
Answer:
Nepal is one of the least developed countries. Solar power is well-founded than electricity. It's better to use solar power because it's a clean resource, the sun provides more energy than we will ever need.
Explanation:
The Earth has a gravitational pull on a single nitrogen molecule (N2) in the air. In comparison, the gravitational pull of the nitrogen molecule on the Earth is:
1.) Weaker, but, no zero.
2.) Zero.
3.) The same size.
4.) Stronger.
Mass Number
The mass number of an atom is the sum of the number of protons and the number of neutrons in the nucleus of an atom.
Mass number = number of protons + number of neutrons For example, you can calculate the mass number of the copper atom listed in Table 4. 29 protons
plus 34 neutrons equals a mass number of 63
Also, if you know the mass number and the atomic number of an atom, you can calculate the number of neutrons in the nucleus. The number of neutrons is
equal to the mass number minus the atomic number. In fact, if you know two of the three numbers-mass number, atomic number, number of neutrons-
you can always calculate the third
The mass number of an atom is 35 and it has 16 protons. How many neutrons does this atom contain?
The atom contains
neutrons
Answer:
3
Explanation:
mass number minus the atomic number
35-32
3
Ball A is thrown horizontally, and ball B is dropped from the same height at the same moment,
Select one:
A Bat B has the greater speed when it reaches the ground
B. Ball A reaches the ground ist
Ball Beaches the ground first
D. D. Balt A has the greater speed when it reaches the ground,
Answer:
a....................
The answer is:
D. Ball A has the greater speed when it reaches the ground
Which of the following types of energy is not associated with a car engine?
A. Kinetic
B. Heat
C. Sound
D. Light
Answer:
D
Explanation:
Does not assosicate with Light
What is meant by uniform motion ? Write with an example.
Answer:
This type of motion is defined as the motion of an object in which the object travels in a straight line and its velocity remains constant along that line as it covers equal distances in equal intervals of time, irrespective of the duration of the time.
Explanation:
In Physics, uniform motion is defined as the motion, wherein the velocity of the body travelling in a straight line remains the same. When the distance travelled by a moving thing, is same at several time intervals, regardless of the time length, the motion is said to be uniform motion.
Your body exerts the same amount of gravitational force on the Moon as the Moon exerts on your body. True or, false?
Answer: TRUE / IT IS TRUE
Explanation:
If you move the north pole of a permanent magnet toward the surface of an aluminum pot, a current will flow through that pot and the pot will become magnetic, repelling your permanent magnet. If you stop the permanent magnet just before it touches the pot and then hold the permanent magnet stationary, the repulsive force between the pot and the permanent magnet will gradually disappear. The repulsive force disappears because the electric current in the pot a) becomes non-magnetic once the permanent magnet stops moving. b) stops increasing and becomes steady once the permanent magnet stops moving. c) becomes an alternating current once the permanent magnet stops moving and the pot’s magnetic poles then flip back and forth rapidly. d) stops flowing
Answer:
the correct one is d
Explanation:
Let's analyze the situation before reviewing the answers.
When the magnet moves towards the pot, an electromotive force is induced by Faraday's law
fem = [tex]- \frac{d \Phi_B }{dt}[/tex] - dfi / dt
[tex]\Phi_B[/tex] = B . A
In the pot, because it is metallic, a current is created and it is in the opposite direction to the variation of magnetic flux.
By stopping the magnet the flux becomes constant and therefore its derivative is zero, therefore there is no electromotive force and consequently no current.
When reviewing the answers, the correct one is d
A bug on a turntable will make more turns per minute if it is located near the center of rotation. True or false?
Please help me this is timed!
The graph below represents the motion of four cars, labeled W, X, Y, and Z.
w
Distance
Time
Which car traveled at a constant speed throughout its motion?
O AW
ОВ. Х
О O c.ru
OD. Z
Answer:
Answer is A
Explanation:
As we know , for constant velocity we get a straight line.
The formula for this problem is s = vt which is similar to a straight line formula like y = mx + c.
If we put here c = 0 we get the formula for distance and velocity.
So the answer is A.
Virtual images exist where no light rays actually can be found.
O A. True
B. False
Answer:
its true
Explanation:
ape x
PLEASE HELP ME I AM TIMED!
Answer:
they all need a source of oxygen
Answer:
B
Explanation:
If the efficiency and mechanical advantage of a certain machine are given as 65 % and 3 respectively.What is the velocity ratio of the machine?
a.3.5 %
b.4.6 %
c.7.9 %
d.11.2 %
Answer:
b. 4.6 %
Explanation:
From the question,
E = M.A/V.R................ Equation 1
Where E = percentage Efficiency of the machine, M.A = machanical accurancy of the machine, V.R = Velocity ratio of the machine
Make V.R the subject of the equation
V.R = M.A/E
Given: M.A = 3, E = 65% = 0.65
Substitute this values into equation 2
V.R = 3/0.65
V.R = 4.6
Hence the right option is b. 4.6 $
An ammeter measures that the current in a simple circuit is 0.22 amps. The circuit is connected to a 55V battery. What is the resistance in the circuit?
Answer: The resistance in the circuit is 250 ohms
Explanation:
According to Ohm's law:
[tex]V=IR[/tex]
where V = voltage = 55 V
I = current in Amperes = 0.22 A
R = Resistance = ?
Putting in the values we get:
[tex]55V=0.22A\times R[/tex]
[tex]R=250ohm[/tex]
Thus the resistance in the circuit is 250 ohms
Conclusion: Suggest an equation relating Felect, q1, q2 and d of the form Felect = k•... where k is a proportionality constant (no need to determine its value). Place the three variables q1, q2 and d on the right side of the equation in a numerator or a denominator; use a power if needed. Your equation should be consistent with your claims made in Challenge #1 and Challenge #2. *I already solved the rest of the worksheet, I only need the conclusion.*
Answer:
[tex]F_{elect} = \frac{kq_1q_2}{d^2}[/tex]
Explanation:
Consider the given variables:
Felect = Electrostatic Force between charged particles
k = Coulomb's Constant
q₁ = magnitude of first charge
q₂ = magnitude of second charge
d = distance between the charges
The relationship among these variables is given by the Coulomb's Law:
[tex]F_{elect} = \frac{kq_1q_2}{d^2}[/tex]
This is the relationship that contains k, q₁, q₂, d on the right-hand side and Felect on the left-hand side.
what is the difference between malleability and ductile ??
Please don't post invalid answer please..!!
Please post correct answer please..!!
Answer:
A malleable material is one in which a thin sheet can be easily formed by hammering or rolling. ... In contrast, ductility is the ability of a solid material to deform under tensile stress.
The gravitational field strength on the moon is 1.63 N/kg. If a rock on the moon weighs 2000N, how
much does the same rock weigh on the earth?
Answer:
12000N
Explanation:
gravity on earth is six times one on the moon
The global winds and moisture belts indicate that large amounts of rainfall occur at
the Earth's equator because air is
it should be rising and converging
The global winds and moisture belts indicate that large amounts of rainfall occur at the Earth's equator because air is rising and converging.
What is Earth's equator?The equator is a large circle that circles the planet Earth, lying in a plane perpendicular to the axis of the planet and being equally spaced from all four geographic poles.
Rainfall in equatorial regions averages 4000mm per year. Every other raining produces about 22 days of precipitation in a month. The equatorial regions have higher temperatures because solar radiation produces a lot of heat there.
The cold air filters down into the lower levels of the atmosphere because the hot air is less dense here than the cold air. The tropical regions become warmer as a result. In the tropical rain belt, the tropical climate predominates.
Learn more about equator here:
https://brainly.com/question/4535514
#SPJ6
i need to figure out A but i’m not sure how
Answer:
cc
Explanation:
If the Sun, Earth, and Moon are lined up as shown, the Earth would have______.
A. Spring tides where there is almost no difference in the tides
B. Spring tides, which is where there are very high tides and very low tides
C. Neap tides where there is almost no difference in the tides.
D. Neap tides, which is where there are very high tides and very low tides
Answer:
The answer is B. Spring tides, which are where there are very high tides and very low tides.
Explanation:
Spring tides occur when the sun and the moon are in alignment with Earth.
At the time of a new moon or full moon when the sun, earth, and the moon are in full alignment the solar tide affects the lunar tide leading to the creation of extra-high high tides, and very low, low tides. The basic reasons for this phenomenon are the gravity of the sun and the moon is acting on the earth oceanPlease thank my answer and vote. (Maybe mark brainliest please)