Answer:
480N
Explanation:
Given data
M1= 1.2kg
U1= 8m/s
V1=7.2 m/s
T= 2ms= 0.002
We know that the impulse expression is
P=FT
M(U1-V1)= FT
substitute
1.2(8-7.2)= F*0.002
1.2*0.8= F*0.002
0.96= F*0.002
F= 0.96/0.002
F=480N
Hence the force is 480N
His eyes are 1.83 m above the floor, and the top of his head is 0.15 m higher. Find the height above the floor of the top and bottom of the smallest mirror in which he can see both the top of his head and his feet.
Answer:
y_lower = 0.915 m, y_superior = 1,905 m
Explanation:
In this exercise we use the law of reflection for a flat mirror.
θ’= θ
To see the feet of the person a ray of light that part of them must reach the bottom of the mirror and its reflection has to reach the eyes.
As the law of reflection the incident and reflected angles are equal, the distance from the floor to the point where the two rays (incident and reflected) touch the mirror must be symmetrical, oses from the floor
y = 1.83 / 2
y = 0.915 m
To see the head, a ray of light that comes from the tip of the head and is reflected in the mirror must reach the eyes. As the head is 0.15 m above the eyes and the incident and reflected rays have the same angle, the mirror must be at half the height, that is, the mirror is 0.075 m below the tip of the head.
In summary
* the bottom of the mirror is 0.915 m from the ground
* the top of the mirror is at 1.83 + 0.075
y_superior = 1,905 m
ground
What is an electron?
(it’s D lol)
Answer:
D
Explanation:
A proton traveling due north enters a region that contains both a magnetic field and an electric field. The electric field lines point due west. It is observed that the proton continues to travel in a straight line due north. In which direction must the magnetic field lines point
Answer:
upward
Explanation:
In the electromagnetic system of force if the direction of motion of proton does not changes it means that the electric and magnetic forces are such a ways that they are cancelling each other's effect.
Since, electric field lines will exert a force on the proton to the west, hence, the magnetic force must force it to the east. It is well known that magnetic force acts perpendicular to the direction of magnetic field. magnetic field should point upward direction.
A block is given an initial velocity of 3.00 m/s up a frictionless incline of angle 20 degrees. How far up the incline does the block slide
Answer:
The distance moved by the block is 1.34 m
Explanation:
Given;
initial velocity of the block, u = 3 m/s
angle of inclination, θ = 20⁰
The net horizontal force acting on the block;
∑Fx = - mgsinθ
Apply Newton's second law of motion, to determine the constant acceleration of the block.
∑Fx = ma
- mgsinθ = ma
-gsinθ = a
Apply the following Kinematic equation, to determine how far up, the block moved before coming to rest.
[tex]V_f^2 = V_i^2 + 2a(x_f -x_i)\\\\0 = V_i^2 + 2[-gsin \theta(x_f-0)]\\\\0 = V_i^2 - 2gsin \theta(x_f)\\\\ 2gsin \theta(x_f) = V_i^2\\\\x_f = \frac{V_i^2}{2gsin \theta} = \frac{(3)^2}{2 \ \times \ 9.8 \ \times \ sin(20)} = 1.34 \ m[/tex]
Therefore, the distance moved by the block is 1.34 m
Why does a transformer require alternating volt age?
1. Alternating voltage leads to electromagnetic induction which is necessary for the transformer to work.
2. Due to economic reasons; alternating voltage is cheaper to produce.
3. If we apply a constant. voltage to the primary coil, it will burn out due to short circuit.
4. No specific reason; the constant voltage would work just as well.
5. The magnetic field produced by the primary coil can reach the secondary coil more easily.
6. Energy can be transferred more efficiently if alternating voltage is used.
Answer:
Alternating voltage leads to electromagnetic induction which is necessary for the transformer to work.
Explanation:
According to Oxford dictionary; an alternating current is "an electric current that reverses its direction many times a second at regular intervals".
A transformer works on the principle of electromagnetic induction. A transformer requires an alternating current which can create a changing magnetic field leading to induced voltage in the coil.
Hence, a transformer requires alternating voltage because alternating voltage leads to electromagnetic induction which is necessary for the transformer to work.
The table shows the relationship between the masses of two objects, the distance between the two objects, and the gravitational force between the objects. A 4-column table with 5 rows. The first column labeled Mass of Object 1 (kilograms) has entries 1, 2, 2, 3, 9. The second column labeled Mass of Object 2 (kilograms) has entries 1, 1, 2, 3, 3. The third column labeled Distance between Objects 1 and 2 (meters) has entries 1, 1, 2, 1, 3. The fourth column labeled Gravitational Force Objects 1 and 2 (Newtons) has entries 1 G, 2 G, 1 G, 9 G, 3G. Which conclusion is supported by the data in the table? An increase in the mass of an object causes the same decrease in the gravitational force. An increase in the distance between the objects causes the same decrease in the gravitational force. An increase in the distance between the objects causes a greater change in the gravitational force than the same increase in mass. An increase in the mass causes a greater change in the gravitational force than the same increase in the distance between the objects. Brainlyest for correct answer!
Answer:
C
Explanation:
edge 2020... Using elimination it's the only one that makes sense.
The statement third "an increase in the distance between the objects causes a greater change in the gravitational force than the same increase in mass" is correct.
What is gravitational force?The gravitational force is a force that attracts all mass-bearing objects. The gravitational force is referred to as attractive because it always strives to pull masses together rather than pushing them apart.
As we know, the gravitational force is given by:
[tex]\rm F = \dfrac{Gm_1m_2}{r^2}[/tex]
Where, G is the gravitational constant.
m1 and m2 are masses.
r is the distance between the masses.
From the data given in the table, shows that:
The gravitational force is indirectly proportional to the square of the distance.
Thus, the statement third "an increase in the distance between the objects causes a greater change in the gravitational force than the same increase in mass" is correct.
Learn more about the gravitational force here:
https://brainly.com/question/12528243
#SPJ2
from
Which energy transformation is correct?
O From A to C, kinetic energy is transformed into
gravitational potential energy.
O From C to D, kinetic energy is transformed into
gravitational potential energy.
O From C to E, gravitational potential energy is
transformed into kinetic energy.
O From D to E, gravitational potential energy is
transformed into kinetic energy.
B. The energy transformation that is correct is From C to D, kinetic energy is transformed into gravitational potential energy.
What is law of conservation of energy?The law of conservation of energy states that energy can neither be created nor destroyed but can be transformed from one form to another.
Energy transformation in the pendulum;
At point A, there's only gravitational potential energy and no kinetic energy, because the pendulum is at rest at A. At point C, it has maximum speed since all of the potential energy is transformed into kinetic energy. Therefore, at this point there is only kinetic energy and no potential energy.At point E, it is the same as at point A, but in opposite side. So, at this point there is no kinetic energy.At points B and D there are both kinetic and potential energy. At point B the kinetic energy is increasing and at point D it is decreasing.Thus, the energy transformation that is correct is From C to D, kinetic energy is transformed into gravitational potential energy.
option B is the correct answer.
Learn more about energy transformation here: https://brainly.com/question/2667612
#SPJ1
Answer:
B is Correct
Explanation:
From C to D, kinetic energy is transformed into gravitational potential energy.
100 g of Ice at -10°C is added into a
liquid juice at 20°c . The temperature of Juice
dropped to l0°c after all the Ice has melted.
Calculate the mass of the Juice responsible
for metting an Ice
Answer:
The mass of the juice responsible for melting the ice is 949.043 grams.
Explanation:
By the First Law of Thermodynamics, we understand that juice releases heat to the ice, which turns into water under the assumption that interactions between the ice-juice system and surroundings are negligible and energy processes are done in steady-state. Since juice is done with water, its specific heat will be taken as of the water. The process is described by the following formula:
[tex]m_{i} \cdot [c_{i}\cdot (T_{1}-T_{2}) - L_{f} + c_{w}\cdot (T_{2}-T_{3})] + m_{w} \cdot c_{w}\cdot (T_{4}-T_{3}) = 0[/tex] (1)
Where:
[tex]m_{i}[/tex] - Mass of ice, in grams.
[tex]m_{w}[/tex] - Mass of the juice, in grams.
[tex]c_{i}[/tex] - Specific heat of ice, in joules per gram-degree Celsius.
[tex]c_{w}[/tex] - Specific heat of water, in joules per gram-degree Celsius.
[tex]L_{f}[/tex] - Latent heat of fusion, in joules per gram.
[tex]T_{1}[/tex] - Initial temperature of ice, in degrees Celsius.
[tex]T_{2}[/tex] - Melting point of water, in degrees Celsius.
[tex]T_{3}[/tex] - Final temperature of the ice-juice system, in degrees Celsius.
[tex]T_{4}[/tex] - Initial temperature of the juice, in degrees Celsius.
If we know that [tex]m_{i} = 100\,g[/tex], [tex]c_{i} = 2.090\,\frac{J}{g\cdot ^{\circ}C}[/tex], [tex]c_{w} = 4.18\,\frac{J}{g\cdot ^{\circ}C}[/tex], [tex]L_{f} = 334\,\frac{J}{g}[/tex], [tex]T_{1} = -10\,^{\circ}C[/tex], [tex]T_{2} = 0\,^{\circ}C[/tex], [tex]T_{3} = 10\,^{\circ}C[/tex] and [tex]T_{4} = 20\,^{\circ}C[/tex], then the mass of the juice is:
[tex]m_{w} = \frac{m_{i}\cdot [c_{i}\cdot (T_{1}-T_{2}) - L_{f} + c_{w}\cdot (T_{2}-T_{3})]}{c_{w} \cdot (T_{3}-T_{4})}[/tex]
[tex]m_{w} = \frac{(100\,g)\cdot \left[\left(2.090\,\frac{J}{g\cdot ^{\circ}C} \right)\cdot (-10\,^{\circ}C) - 334\,\frac{J}{g} +\left(4.18\,\frac{J}{g\cdot ^{\circ}C} \right)\cdot (-10\,^{\circ}C) \right]}{\left(4.180\,\frac{J}{g\cdot ^{\circ}C} \right)\cdot (-10\,^{\circ}C)}[/tex]
[tex]m_{w} = 949.043\,g[/tex]
The mass of the juice responsible for melting the ice is 949.043 grams.
A wooden block meauring 40cm x 10cm x 5cm has a mass 850gm . find the density of wood?
please answer me.
Answer:
Explanation:
Density = Mass / Volume = 850 / 40*10*5 = 0.425 g /cm^3
In a photoelectric effect experiment you illuminate a metal with light of an unknown wavelength and measure the maximum kinetic energy of the photoelectrons to be 0.75 eV. Then you illuminate the same metal with light of a wavelength known to be 2/3 of the first wavelength and measure a maximum kinetic energy of 1.8 eV for the photoelectrons.
Required:
a. Find the first wavelength, in nanometers
b. Find the metals work function, in electron volts
Answer:
A.) 1658 nm
B.) 1.05 ev
Explanation:
Given that in a photoelectric effect experiment you illuminate a metal with light of an unknown wavelength and measure the maximum kinetic energy of the photoelectrons to be 0.75 eV. Then you illuminate the same metal with light of a wavelength known to be 2/3 of the first wavelength and measure a maximum kinetic energy of 1.8 eV for the photoelectrons.Required:
a. Find the first wavelength, in nanometers
The formula to use is:
E = hf
Where f = c/ wavelength.
C = speed of light.
Convert the electron volts to Joule.
0.75 × 1.6 × 10^-19 = 1.2 × 10^-19 J
Substitute the values into the formula
1.2 × 10^-19 = (6.63 × 10^-34 × 3 × 10^8) ÷ wavelength
Wavelength = (6.63×10^-34 × 3×10^8) ÷ 1.2×10^-19
Wavelength = 1.6575 × 10^-6 m
Therefore, the wavelength of the first light in nanometers will be
Wavelength = 1658 nm
b. Find the metals work function, in electron volts
The metal works function will be:
WF = 1.8 - 0.75 = 1.05 eV
Consider a loop of wire with a resistor. In the same plane, (with switch S closed) a long wire has a current I flowing from left to right. R I S If switch S is closed for a long period of time, and then suddenly opened, what is the direction of the induced current through R as the current I rapidly decreases
Solution :
The given figure is a loop of a wire with a resistor.
When the switch S is closed for long time and is suddenly opened, the direction of the induced current can be find out by using the rule of right hand screw. According to the right hand screw rule, the direction of the magnetic field at the loop is in the direction that points outwards. The strength of the current rapidly decreases as it is switch off and the magnetic flux that is linked with the loop wire will also decrease.
According to the Lenz's law, the direction of the induced current must be such [tex]$\text{that it opposes}$[/tex] the decrease in the magnetic flux. It means the direction of the magnetic field must be outwards and also normal to the plane of the screen. The direction of the induced anti clockwise or from right to left in the resistance.
The amount of change between the crest or trough of a wave and the normal
A wave has a speed of 450 m/s and a frequency of 5 Hz. What is its wavelength?
Give you answer to a 1 decimal place.
Your Answer:
Answer
the wavelength is 90
Explanation:
Will give brainliest! 50 points!!!
When the polarity of a moving magnet through a coil doubles the electromagnetic field _________.
A. Increases
B. Decreases
C. Stays the same
Answer:
A. Increases
Explanation:
Mark as Brainliest
What is the total amount of force needed to keep a 6.0 kg object moving at speed
of 5.0 m/s? (F=ma)
A. 30 N
B. 60 N
C.ON
D. 10 N
Explain what happens during stages A and B.
Say the turbine is 10 feet in diameter (that's the radius of the dashed circle). Also say that the coil has 100 turns and has a square cross-section with a length of 10 feet and a height of 6 feet. Say that the magnetic rotor has the same height but is only 2 feet wide, it has a magnetic field strength is 0.1T, and it is rotating at 60Hz (note this is not the angular frequency). A typical turbine supplies 10kW of power. Use Faraday's law to find the induced emf in the coil and the amount of induced current.
Answer:
a. ε = 21,014sin(120πt) V
b. 0.476cosec(120πt)
Explanation:
a. Induced emf
We know the induced emf, ε = -dΦ/dt where Φ = magnetic flux through coil = NABcosθ where N = number of turns of coil =, 100, A = area of coil = 10 ft × 6 ft = 60 ft² = 60 × 1 ft² = 60 × (0.3048)² m² = 5.574 m², B = magnetic field strength = 0.1 T and θ = angle between B and normal to A = ωt.
So, Φ = NABcosθ = 100 × 5.574 m² × 0.1 T cosθ = 55.74cosθ Tm²
So, ε = -dΦ/dt = ε = -d(55.74cosθ Tm²)/dt = -d(55.74cosθ Tm²)/dθ × dθ/dt = -55.74 ×(-sinθ) Tm²)/dθ × ω (ω = dθ/dt = angular frequency of shaft = 2πf where f = frequency of rotor = 60 Hz )
ε = 55.74sinθ Tm²) × 2πf
ε = 55.74sinθ Tm²) × 2π(60 Hz)
ε = 6689πsinθ V
ε = 21,014sinθ V
ε = 21,014sinωt V
ε = 21,014sin(2πft) V
ε = 21,014sin(2π(60 Hz)t) V
ε = 21,014sin(120πt) V
b. Current in coil
Since power P = Iε where I = current and ε = induced emf = 21,014sinθ V.
Since power, P = 10 kW = 10000 W
I = P/ε
= 10000 W/21,014sinθ V
= 0.476/sinθ
= 0.476cosecθ
= 0.476cosecωt
= 0.476cosec(120πt)
The maximum current is obtained when θ = 90°
I = 10000 W/21,014sin90 V
I = 10000 W/21,014 V
I = 0.476 A
I = 476 mA
If an object is placed 10cm in front of a converging lens that has a focal length of 15cm. What are the properties of the image?
Answer:
Enlarged [Size]
Virtual and Erect [Nature]
On the same side of the lens as the object [Position]
Explanation:
Wha is the definition of health?
Facts about ecstasy
Please help!!! Explain the type of graph that could be used for the data below.
In a given cartesian coordinate system a particle is in the position (initial vector position) ( 9.2 , 3.1 ) meters. After 10 seconds, the particle is in the position (final vector position) ( 72.2, 77.2 ) meters. What is the magnitude of the average velocity of the particle during the given time interval, in m/s
Answer:
Thus, the average velocity is 9.73 m/s.
Explanation:
The velocity is given by the rate of change of position.
initial position, A = (9.2, 3.1) m
final position, B = (72.2, 77.2) m
time, t = 10 s
The velocity is given by
[tex]\overrightarrow{v} =\frac{\overrightarrow{B}-\overrightarrow{A}}{t}\\\overrightarrow{v}=\frac{(72.2-9.2)\widehat{i} - (77.2-3.1)\widehat{j}}{10}\\\overrightarrow{v}=\frac{63 \widehat{i} - 74.1\widehat{j}}{10}\overrightarrow{v} =6.3 \widehat{i} - 7.41 \widehat{j}\\v =\sqrt{6.3^{2}+7.41^{2}}v = 9.73 m/s[/tex]
the sun transfers heat to earth through ___ this method of heat transfer is evidence that ___ is not necessary for heat to move from place to place
Answer:
electromagnetic waves, physical contact
Explanation:
The sun transfers heat to earth through electromagnetic radiation. This method of heat transfer is evidence that direct contact is not necessary for heat to move from place to place.
What is meant by heat transfer ?Heat transfer is defined as the flow of heat or thermal energy from one point to another due to the temperature difference between the two points.
Here,
Due to the temperature difference between, heat transfer occurs between two points through various methods such as conduction, convection and radiation.
Conduction is the process of heat transfer through which heat is transferred between two objects that are in direct contact with each other. It can occur in solids, liquids and gases.
Convection is the process of heat transfer through which the heat is transferred by the movement of fluids. Air and water currents are the examples for it.
Radiation is the process of heat transfer in which the heat is transferred in the form of electromagnetic waves.
The heat energy from the sun reaches the earth through the phenomenon called electromagnetic radiation. Mainly infrared radiations carry the heat towards earth.
Unlike conduction and convection, radiation does not require any matter to transfer the heat energy.
Hence,
The sun transfers heat to earth through electromagnetic radiation. This method of heat transfer is evidence that direct contact is not necessary for heat to move from place to place.
To learn more about heat transfer, click:
https://brainly.com/question/16951521
#SPJ7
You have just landed your first job as a structural engineer and you have been asked to design a regional airport for small planes. Your manager informs you that the planes that will use this runaway must reach a speed before takeoff of at least 28.1 m/s, and can accelerate at 2 m/s2. What is the minimum length your runaway must have to facilitate a safe take off
Answer: [tex]197.40\ m[/tex]
Explanation:
Given
final velocity at takeoff [tex]v=28.1\ m/s[/tex]
Acceleration of the plane can be [tex]a=2\ m/s^2[/tex]
Initial velocity is zero for the plane i.e. [tex]u=0[/tex]
Using the equation of motion
[tex]\Rightarrow v^2-u^2=2as\quad [\text{s=displacement}]\\\text{Insert the values}\\\Rightarrow (28.1)^2-0=2\times 2\times s\\\\\Rightarrow s=\dfrac{789.61}{4}\\\\\Rightarrow s=197.40\ m[/tex]
Thu,s the minimum length must be [tex]197.40\ m[/tex]
A student rubs a rubber balloon on their hair for several seconds. The student then rubs a second rubber balloon on her hair for the same length of time. The student determines that the first rubber balloon is repelled by the second rubber balloon, but the first rubber balloon is attracted to her hair. Which of the following claims, with appropriate evidence, if any, supports the notion of the two- charge model? Justify your selection.
A. The first rubber balloon is repelled by the second rubber balloon, but the first rubber balloon is attracted to the hair. These results show that two charges must exist because certain combinations of charges attract and certain combinations of charges repel.
B. The first rubber balloon is repelled by the second rubber balloon. This result shows that the charge of both objects must have the same sign.
C. The first rubber balloon is attracted to the hair. This result shows that the charge of both objects must be opposite in sign.
D. None of the claims nor evidence support the notion of the two-charge model.
Answer:
Option A
Explanation:
In this experiment, when balloon is rubbed on the chair electrons are transferred from the hair to the surface of the balloon thereby making balloon negatively charged and hair positively charged. When two negatively charged balloon are brought close to each other, they repel while when balloon is brought closer to the hair, they attract each other
Hence, option A is correct
A radio station broadcasts with a carrier frequency of 920 kHz. What is the wavelength of the radio waves?
a. 276 m
b. 175 m
c. 22.6 m
d. 326 m
e. 226 m
Answer: 326m
Explanation:
To find the the wavelength of the radio waves, we can use the equation:
Wavelength = c/f
where,
c = 3 × 10^8 m/s
f = 920 × 10^3 kHz
Wavelength = 3 × 10^8 / 920 × 10³
Wavelength = 326.08696
Wavelength = 326m
Define 1ohm resistance
Answer:
1 ohm is equal to one volt (V)/ one ampere (1A) 1 Ohm is defined as the resistance of a conductor with a potential difference of 1 volt applied to the ends through which 1-ampere current flows. Ohms is the SI unit of electrical resistance.
Explanation:
I hope it's help u
Which force binds the nucleus together despite the fact there are protons in close proximity to each other?
A.weak nuclear
B
strong nuclear
C
gravitational
D
electromagnetic
Answer:
The correct answer is B. Strong Nuclear.
Explanation:
An atom contains protons, neutrons, and electrons. The nucleus of an atom consists of bound protons and neutrons (nucleons). The negatively charged electrons are attracted to the positively charged protons and fall around the nucleus, much like a satellite is attracted to the gravity of the Earth. The positively-charged protons repel each other and aren't electrically attracted or repelled to the neutral neutrons, so you may wonder how the atomic nucleus sticks together and why protons don't fly off.
The explanation for why protons and neutrons stick together is known as "the strong force." The strong force is also known as the strong interaction, color force, or strong nuclear force. The strong force is much more powerful than the electrical repulsion between protons, however, the particles have to be close to each other for it to stick them together.
A cylindrical space colony 8.00 km in diameter and 30.0 km long has been proposed as living quarters for future space explorers. Such a habitat would have cities, land, and lakes on the inside surface and air and clouds in the center. All this would be held in place by the rotation of the cylinder about the long axis. How fast would such a cylinder have to rotate to produce a 1-g gravitational field at the walls of the cylinder
Answer:
ω = 0.05 rad/s
Explanation:
In order to produce the acceleration equal to the acceleration due to gravity at the surface of Earth, the centripetal acceleration must be equal to the value of g:
[tex]a_c = g\\g = \frac{v^2}{r}\\\\but,\ v=r\omega\\therefore,\\\\g = \omega^2r\\\\\omega = \sqrt{\frac{g}{r}}[/tex]
where,
ω = angular speed = ?
g = acceleration due to gravity on the surface of the Earth = 9.81 m/s²
r = radius of cylinder = 8 km/2 = 4 km = 4000 m
Therefore,
[tex]\omega = \sqrt{\frac{9.81\ m/s^2}{4000\ m}}[/tex]
ω = 0.05 rad/s
A pulley system uses a flat belt of c.s.a. 4x100 mm2 and density 11x100 kg/m3. The angle of lap is 165o on the smaller wheel. The coefficient of friction is 0.39. The maximum force allowed in the belt is 637 N. Calculate the power (kW) transmitted when the belt runs at 13 m/s and centrifugal force is included.
Answer:
Note that the angle of lap is 165 degrees at the question above
So the power (kW) transmitted when the belt runs at 13 m/s and centrifugal force is included = 3.79782kW
Explanation:
Centrifugal force, Fc = pAv^2
Where p = density, A = c.s.a. v = veelocity
= 11x100 kg/m3 X 4x100 mm2 X (13 m/s)^2
= 1100 kg/m3 X 400 mm2 x 10^-6 X 169m/s
= 74.36N
P v (f - Fc) (1-e^-μθ)
The θ = (165 degrees ÷ 180 degrees) X π = 2.878 rads (π = 3.14)
So power p, = 10 (637 N - 74.36N) (1 - e^-0.39 x 2.878)
= 10 X 562.64 X 0.675
P = 3797.82 watts = 3.79782kW