Answer:
833.9kg that's the answer
An image is a copy of an objecí formed by what light
Answer:
Plane mirror
Explanation:
A virtual image is a copy of an object formed at the location from which the light rays appear to come.
A light wave passes through an aperture (that is, a narrow slit). When it does so, the degree to which the wave spreads out will be...
Explanation:
Single slit diffraction
Diffraction is the phenomenon of spreading out of waves as they pass through an aperture or around objects. Diffraction occurs when the size of the aperture or obstacle is of the same order of magnitude as the wavelength of the incident wave. For very small aperture sizes, the vast majority of the wave is blocked. in case of large apertures the wave passes by or through the obstacle without any significant diffraction.
A nuclear explosion results in a mass decrease of 2.10 g. how much energy is released during this explosion?(c = 3.00 x 108 m/s)
a. 2.25 x 10^12J
b. 1.89 x 10^13J
c. 1.89 x 10^14J
d. 6.30 x 10^5J
Answer: c. 1.89 x 10^14 J
Explanation:
By Einstein's equation, we know that:
E = m*c^2
Where m is the mass-consumed in this case:
m = 2.10g
And we must rewrite this in Kg, knowing that:
1kg = 1000g
Then:
m = 2.10g = (2.10/1000) kg = 0.0021 kg
And c is the speed of light:
c = 3*10^8 m/s.
Then the energy will be:
E = 0.0021 kg*(3*10^8 m/s)^2 = 1.89*10^14 Joules.
The correct option is:
c. 1.89 x 10^14J
A nearsighted person has a far point of 40cm. What power spectacle lens is needed if the lens is 2cm from the eye
Answer:
The value is [tex]p = - 2.63 \ Diopters[/tex]
Explanation:
From the question we are told that
The value of the far point is [tex]a = 40 \ cm = 0.4 \ m[/tex]
The distance of the lens to the eye is [tex]b = 2 \ cm = 0.02[/tex]
Generally
[tex]1 Diopter = > 1 m^{-1}[/tex]
Generally the power spectacle lens needed is mathematically represented as
[tex]p = \frac{1}{d_o } + \frac{1}{d_i}[/tex]
Here [tex]d_o[/tex] is the object distance which for a near sighted person is [tex]d_o = \infty[/tex]
And [tex]d_i[/tex] is the image distance which is evaluated as
[tex]d_i = b - a[/tex]
=> [tex]d_i = 0.02 - 0.4[/tex]
=> [tex]d_i = -0.38 \ m[/tex]
So
[tex]p = \frac{1}{\infty } + \frac{1}{-0.38}[/tex]
=> [tex]p = 0 - 2.63[/tex]
=> [tex]p = - 2.63 \ Diopters[/tex]
are aliens real in 2020
Answer:
i believe that they are or there's something out there
Explanation:
:)
Alex, parked by the side of an east-west road, is watching car P, which is moving in a westerly direction. Barbara, driving east at a speed 52 km/h, watches the same car. Take the easterly direction as positive. If Alex measures a speed of 78 km/h for car P, what velocity will Barbara measure?
Answer:
[tex]v_{PB} = 130\ km/h[/tex]
Explanation:
Since, Alex is at rest. Therefore, the speed measured by him will be the absolute speed of car P. Therefore, taking easterly direction as positive:
[tex]Absolute\ Velocity\ of\ Car\ P = v_{P} = -78\ km/h[/tex]
And the absolute velocity of Barbara's Car is given as:[tex]Absolute\ Velocity\ of\ Barbara's\ Car = v_{B} = 52\ km/h[/tex]
Now, for the velocity of Car p with respect to the velocity of Barbara's Car can be given s follows:
[tex]Velocity\ of\ Car\ P\ measured\ by\ Barbara = v_{PB} = v_{B}-v_{P}\\\\v_{PB} = 52\ km/h-(-78\ km/h)[/tex]
[tex]v_{PB} = 130\ km/h[/tex]
Which wave has high enough energy to cause damage to skin and sometimes cancer?
Answer: All UV can have harmful effects on biological matter (such as causing cancers) with the highest energies causing the most damage.
Explanation:
Two students (90.0 kg and 60.0 kg) on roller skates face-to-face push against each other. The 90.0 kg student moves at 5.0 m/s just after their hands lose contact. What is the velocity of the other student?
Given that,
Mass of student 1, m₁ = 90 kg
Mass of student 2, m₂ = 60 kg
Speed of student 1, v₁ = 5 m/s
To find,
The velocity of the other student.
Solution,
Using the conservation of momentum to find the velocity of the other student. Let it is v₂.
[tex]m_1v_1=m_2v_2\\\\v_2=\dfrac{m_1v_1}{m_2}\\\\v_2=\dfrac{90\times 5}{60}\\\\=7.5\ m/s[/tex]
So, the velocity of the other student is 7.5 m/s.
Two wave pulses pass each other on a string. The pulse traveling toward the right has positive amplitude, whereas the pulse traveling toward the left has equal amplitude in the negative direction. What happens when they occupy the same region of space at the same time?
a. constructive interference occurs
b. destructive interference occurs.
c. a standing wave is produced.
d. a traveling wave is produced.
e. a wave pulse is produced.
Answer:
destructive interference occurs
. Emily pushes a 38.8 kg grocery cart of groceries by exerting a 76.0 N force on the handle inclined at 40.0 degrees below the horizontal. What are:
a. The horizontal and vertical components of Emily’s force
b. The acceleration of the cart?
Answer:
a) [tex]F_{x} = 58.2 N[/tex]
[tex] F_{y} = 48.9 N [/tex]
b) a = 1.5 m/s²
Explanation:
a) The horizontal and vertical components of Emily's force can be found knowing the angle and the exerted force.
Since the handle is inclined at 40.0° below the horizontal we have:
[tex] F_{x} = |F|*cos(\theta) = 76.0 N*cos(40) = 58.2 N [/tex]
[tex] F_{y} = |F|*sin(\theta) = 76.0 N*sin(40) = 48.9 N [/tex]
b) The acceleration of the car can be calculated as follows:
[tex] F_{x} = ma [/tex]
We used the horizontal component of the force because the cart is moving in that direction.
[tex] a = \frac{F_{x}}{m} = \frac{58.2 N}{38.8 kg} = 1.5 m/s^{2} [/tex]
Hence, the acceleration of the car is 1.5 m/s².
I hope it helps you!
At 3.00 m from a source that is emitting sound uniformly in all directions, the sound level (b) is 60.0 dB.
How many meters from the source would the sound level be one-fourth the sound level at 3.00 m?
Given that,
At 3.00 m from a source that is emitting sound uniformly in all directions, the sound level is 60.0 dB.
To find,
The distance from the source would the sound level be one-fourth the sound level at 3.00 m.
Solution,
The intensity from a source is inversely proportional to the distance.
Let I₁ = 60 dB, r₁ = 3 m, I₂ = 60/4 = 15 dB, r₂ =?
Using relation :
[tex]\dfrac{I_1}{I_2}=\dfrac{r_2^2}{r_1^2}\\\\r_2^2=\dfrac{I_1r_1^2}{I_2}\\\\r_2^2=\dfrac{60\times (3)^2}{15}\\\\r_2=6\ m[/tex]
So, at a distance of 6 m the sound level will be one fourth of the sound level at 3 m.
The scientific method can easily be misinterpreted as ___________. Question 1 options: a great magical trick, or slide of hands, rather than factual an "auto mechanics" guide to Science Investigation a "cookbook" recipe for performing scientific investigations the perfect method for finding the answers to all questions
Answer:
I think the answer is
a "cookbook" recipe for performing scientific investigations
Explanation:
if a certain car, going with speed v1, rounds a level curve with a radius r1, it is just on the verge of skidding. if its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is:
Answer:
The correct answer is 4R1
Explanation:
According to the given scenario ,the radius of the tightest curve on the same road without skidding is as follows:
As we know that
Centeripetal Acceleration is
= v^2 ÷ r
In the case when velocity becomes 2 times so the r would be 4 times
So, the radius of the tightest curve on the same road without skidding is 4R1
0.0884 moles of a diatomic gas
are in a piston. When the piston
is compressed, the temperature
drops by 18.8 K, and 83.7 J of
heat flow out. Find W.
(Be careful with + and - signs.
+W = expansion, +Q = added,
+AU = temp goes up)
(Unit = J)
Answer:
W = - 118.24 J (negative sign shows that work is done on piston)
Explanation:
First, we find the change in internal energy of the diatomic gas by using the following formula:
[tex]\Delta\ U = nC_{v}\Delta\ T[/tex]
where,
ΔU = Change in internal energy of gas = ?
n = no. of moles of gas = 0.0884 mole
Cv = Molar Specific Heat at constant volume = 5R/2 (for diatomic gases)
Cv = 5(8.314 J/mol.K)/2 = 20.785 J/mol.K
ΔT = Rise in Temperature = 18.8 K
Therefore,
[tex]\Delta\ U = (0.0884\ moles)(20.785\ J/mol.K)(18.8\ K)\\\Delta\ U = 34.54\ J[/tex]
Now, we can apply First Law of Thermodynamics as follows:
[tex]\Delta\ Q = \Delta\ U + W[/tex]
where,
ΔQ = Heat flow = - 83.7 J (negative sign due to outflow)
W = Work done = ?
Therefore,
[tex]-83.7\ J = 34.54\ J + W\\W = -83.7\ J - 34.54\ J\\[/tex]
W = - 118.24 J (negative sign shows that work is done on piston)
Answer:
-49.2
Explanation:
Trust me bro
Is electricity matter?
EXPLAIN.
Answer:
Yes it is matter
Explanation:
In physics, usually the word "electricity" isn't really used. "Electric current" is more common, and is defined as the flow of charges, where the charges are held by particles (electrons). Electrons have mass, so they are definitely matter.
HELP right awayyy !!!
Answer:
Question 4 is actually Acceleration
Which is the luminous object?
what is the main cause of seafloor spreading?
Answer:
As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense.
Explanation:
Answer: The main cause of sea floor spreading are the directions and force of the moving tectonic plates.
Explanation:
What is the period of an object that makes 6 revolutions a minute?
Answer:
T = 10 s
Explanation:
First, we need to find the frequency of the object as follows:
[tex]Frequency = f = \frac{Speed\ in\ rpm}{60}[/tex]
where,
Speed = Angular Speed = 6 rpm
Therefore,
[tex]f = \frac{6\ rpm}{60}\\\\f = 0.1\ Hz[/tex]
Now, for time period (T):
[tex]Time\ Period = T = \frac{1}{f}\\\\T = \frac{1}{0.1\ Hz}\\\\[/tex]
T = 10 s
1. You are hired to lift 25 kg crates a vertically 1.0 m from the ground onto a truck. How many crates would you have to load onto the truck in 1 minute for your average power output in lifting the crates to be 110 W
Answer:
The number of crate to be lifted is 27
Explanation:
Given;
mass of the crates, m = 25 kg
height in which the crate is lifted, h = 1.0 m
power output, P = 110 W
time to complete the task, t = 1 minutes = 60 s
The input energy is equal to the gravitational energy due to height the crate is lifted is given as;
E(input) = mgh
E(input) = 25 x 9.8 x 1
E(input) = 245 J
Output energy is given as;
E(output) = P x t
E(output) = 110 x 60
E(output) = 6600 J
Let the number of crate to be lifted = n
n x E(input) = E(output)
n x 245 = 6600
n = 6600 / 245
n = 27 crates
Conveyor belts are often used to move packages around warehouses. The conveyor shown below moves packages at a steady 4.0 m/s. A 500 N employee decides to catch a ride by sitting on a 1,000 N box for a 50 m trip as shown below:
What is the work done by the employee on the box?
Answer:
0 j
Explanation:
The work done by the employee on the box at the given zero displacement is 0 J.
The given parameters;
Constant velocity of the conveyor, v = 4 m/sWeight of the employee, W = 500 NWeight of the box, W = 1,000 NDistance of the trip, h = 50 mThe work done by the employee on the box is calculated as follows;
W = Fd
where;
F is the applied force on the box by employee = weight of the employeed is the distance through which the box is movedSince the employee sits on the box without moving it, the distance moved by the box = 0
W = 500 x 0
W = 0 J
Thus, the work done by the employee on the box is 0 J.
Learn more about work done and displacement here: https://brainly.com/question/8635561
the question is in a picture
Answer:
same for all objects
Explanation:
earth pulls every object by same force of gravity
What causes the magnetic field around the wire?
Magnetic field
O A. An electric current
O B. An electric field
PREVIOUS
An electric current causes the magnetic field around the wire. The correct answer is A.
The magnetic field around a wire is caused by the flow of electric current through the wire. When an electric current passes through a wire, it generates a magnetic field that forms circular lines of magnetic flux around the wire. This phenomenon is described by Ampere's law, which states that a magnetic field is produced by an electric current and its strength is directly proportional to the magnitude of the current.
The relationship between the electric current and the magnetic field can be understood using the right-hand rule. If you wrap your right hand around the wire with your thumb pointing in the direction of the current, the curled fingers indicate the direction of the magnetic field lines.
Therefore, an electric field is generated by an electric charge, not by an electric current. While an electric field can exist around a wire if there is a potential difference (voltage) applied across it, it is the flow of electric current that primarily generates the magnetic field.
To learn more about the electric field click:
brainly.com/question/8971780
#SPJ1
Energy stored because of an object's height above the Earth's surface is_____energy.
nuclear
gravitational
electrical or chemical
A ball is thrown horizontally at a height of 1.5 meters at a velocity of 70 m/s. Assume no air resistance. How long until the ball reaches the ground?
0.25 s
0.38 s
0.55 s
0.67 s
Answer:
[tex]t = 0.55[/tex]
Explanation:
Given
[tex]Height, s = 1.5m[/tex]
[tex]Velocity, v = 70m/s[/tex]
Required
Determine the time to hit the ground
Using free fall formula:
[tex]S = \frac{1}{2}gt^2[/tex]
Take g as 9.8 and substitute value for S
[tex]1.5 = \frac{1}{2} * 9.8 * t^2[/tex]
[tex]1.5 = 4.9 * t^2[/tex]
Make t^2 the subject
[tex]t^2 = \frac{1.5}{4.9}[/tex]
[tex]t^2 = 0.30612244898[/tex]
Solve for t
[tex]t = \sqrt{0.30612244898[/tex]
[tex]t = 0.55[/tex] -- approximated
A particular engine has a power output of 5 kW and an efficiency of 30%. If the engine expels 6464 J of thermal energy in each cycle, find the heat absorbed in each cycle. Answer in units of J.
Answer:
The heat absorbed in each cycle is 9,234.286 J
Explanation:
Given;
power output, P = 5 kW = 5,000 W
efficiency of the engine, e = 30 % = 0.3
thermal heat expelled, [tex]Q_c[/tex] = 6464 J
let the heat absorbed = [tex]Q_h[/tex]
The efficiency of the engine is given as;
[tex]e = \frac{W}{Q_h} = \frac{Q_h-Q_c}{Q_h} = \frac{Q_h}{Q_h} - \frac{Q_c}{Q_h} = 1-\frac{Q_c}{Q_h}\\\\e = 1-\frac{Q_c}{Q_h}\\\\0.3 = 1-\frac{Q_c}{Q_h}\\\\\frac{Q_c}{Q_h} = 1-0.3\\\\\frac{Q_c}{Q_h} = 0.7\\\\Q_h = \frac{Q_c}{0.7} \\\\Q_h = \frac{6464}{0.7} = 9,234.286 \ J.[/tex]
Therefore, the heat absorbed in each cycle is 9,234.286 J.
3. Two balls are rolling toward each other. One has a momentum of 85kg*m/s, and the other has a momentum of -85kg*m/s. What will be the total momentum of the system after they collide? In what direction will they move after they collide if it is an inelastic collision? Answer:
Answer:
The total momentum is zero.
Explanation:
This problem can be solved by applying the momentum conservation theorem and the amount of motion. This theorem tells us that the amount of motion is conserved before and after a collision.
In the next equation, we will write to the left of the equal sign the amount of motion before the collision and to the right the amount of motion after the collision.
[tex](P_{1})-(P_{2})=P_{3}[/tex]
where:
P₁ = momentum of the ball moving to the right, before the collision = 85 [kg*m/s]
P₂ = momentum of the ball moving to the left, before the collision = - 85 [kg*m/s]
P₃ = Final momentum after the collision [kg*m/s]
[tex](85) - 85 = P_{3}\\P_{3}= 0[/tex]
There is no movement of any of the balls, they remain at rest after the impact.
en the current in one coil changes at a rate of 3.2 A/s, an emf of 5.7 is induced in a second, nearby coil. What is the magnitude of the mutual inductance of the two coils
Given that,
The rate of change of current = 3.2 A/s
Emf induced in the coil = 5.7 V
To find,
The magnitude of the mutual inductance of the two coils.
Solution,
The mutual inductance between the coils is given by the formula as follows :
[tex]\epsilon=M\dfrac{dI}{dt}\\\\M=\dfrac{\epsilon}{\dfrac{dI}{dt}}\\\\M=\dfrac{5.7}{3.2}\\\\=1.78\ H[/tex]
So, the mutual inductance of the two coils is 1.78 H.
An object 2.7 cmtall is placed12 cmin front of a mirror. •What type of mirror and what radius of curvature are needed to createan upright image that is 5.4 cm in height? •What is the magnification of the image?
Answer:
a. Concave mirror, radius of curvature = 16 cm b. magnification = 2
Explanation:
a. Since the image is upright and larger than the object, we need a concave mirror.
We know image height, h'/object height, h = -image distance, d'/object distance, d
h'/h = -d'/d
Using the real is positive convention,
h'= + 5.4 cm, h = + 2.7 cm and d = + 12 cm.
So, + 5.4 cm/+ 2.7 cm = -d'/+ 12 cm
2 = -d'/12
d' = -2 × 12 cm
= -24 cm
Using the mirror formula 1/d + 1/d' = 2/r where r = radius of curvature of the mirror
1/+12 + 1/- 24 = 2/r
1/12(1 - 1/2) = 2/r
1/12(1/2) = 2/r
1/24 = 2/r
r/2 = 24
r = 2 × 24
r = 48 cm
b.
magnification = image height, h'/object height,h = + 5.4 cm/+ 2.7 cm = 2
What is the purpose of a resistor
Answer:
So we can have energy for electronics. It limits the flow of electric current
Explanation:
It’s in the answer!
Answer:
Basically, the function of a resistor is always to oppose the flow of current through it and the strength of this opposition is termed as its resistance.