Answer:
friction reduces the efficiency of machines, thus we must reduce the friction force that is acting upon it.
Answer:
Because it causes a lot of wear and tear in machine parts that move against each other. It erodes the surfaces and destroys their symmetries
Explanation:
giving me the points are enough
Answer:
the product of mass and velocity
....in my syllabus
The hair dryer has a plastic case so there is no need for an earth wire connection in the plug ,explain why the hair dryer is still safe to use.
Answer:
plastics are unable to conduct electricity and heat due to there being no free flowing electrons, meaning they are safe to use.
Explanation:
A toy car with a mass of 5.5 kg is moving horizontally over flat ground at a speed of 2.1 m/s. An unknown force then directly pushes the car for a distance of 3 meters, after which the car has a speed of 7.3 m/s. You may assume that air resistance and friction are both negligible. What was the magnitude of the unknown force
Answer:
The magnitude of the unknown force is 44.8 N.
Explanation:
The force can be found with Newton's second law:
[tex] F = ma [/tex]
Where:
m: is the mass of the toy car = 5.5 kg
a: is the acceleration
F: is the force =?
We can calculate the acceleration with the following kinematic equation:
[tex] v_{f}^{2} = v_{0}^{2} + 2ad [/tex]
Where:
[tex] v_{f} [/tex]: is the final speed = 7.3 m/s
[tex] v_{0} [/tex]: is the initial speed = 2.1 m/s
d: is the distance traveled = 3 m
Hence, the acceleration is:
[tex] a = \frac{v_{f}^{2} - v_{0}^{2}}{2d} = \frac{(7.3 m/s)^{2} - (2.1 m/s)^{2}}{2*3 m} = 8.15 m/s^{2} [/tex]
Finally, the magnitude of the force is:
[tex]F = ma = 5.5 kg*8.15 m/s^{2} = 44.8 N[/tex]
Therefore, the magnitude of the unknown force is 44.8 N.
I hope it helps you!
What kind of circuit is the one shown below?
A. Series
B. Parallel
C. Open
D. Combination
That's a parallel circuit. (B)
When current from Point-A reaches the 3-way intersection just to the right of Point-B, it has to make a choice: Either turn left, go through B, and light the lower bulb, or go straight and light the upper bulb.
A circuit that has any "decision" points in it is a parallel circuit. What happens in the real world is: The current splits up. Some of the current that reaches the intersection turns left toward Point-B, and the rest of it goes straight up.
A series circuit is one in which there's only one possible path all the way around. There are no intersections of more than 2 roads, and no electron ever has to decide which way to flow.
An open circuit is one in which there's a break somewhere along the line and electrons can't jump across it. It's like a railroad where a big piece is cut out of the track somewhere. So no trains can travel on that route, and there's no current flowing anywhere in the circuit.
I'm not so sure about a "combination" circuit. I guess you could give that name to a complicated circuit that has some series parts and some parallel-parts. Personally, I'd call that a "series-parallel" circuit. But it really doesn't matter right now. Whatever the word means, the circuit in the picture is definitely not a "combination" circuit.
Answer:
B. Parallel Circuits
Explanation:
A parallel circuit is constructed by connecting the terminals of all the individual load devices so that the same value of voltage appears across each component. In a parallel circuit, charge divides up into separate branches such that there can be more current in one branch than there is in another.
hope i helped
If a roller coaster train has a potential energy of 1,500 J and a kinetic energy of 500 J as it starts to travel downhill, what is its total energy
Its total mechanical energy is 2,000 J.
We don't have enough information to say anything about its heat energy, its chemical energy, or the energy due to any electrical charge it may be carrying or any magnetic field it may have.
What would be the acceleration in a body moving with uniform velocity and why?
Explanation:
The derivative of a constant term is always 0. So the acceleration of the body would be zero. Hence, the acceleration of a body moving with uniform velocity will always be zero.
hope it helps you
To what height, h, would the pendulum bob rise after a single swing if it was being released from the height of 0.80 m
Answer:
0.80 m
Explanation:
Neglecting friction, the total mechanical energy of the pendulum is constant.
E = K + U where K = kinetic energy and U = potential energy.
At its release point of 0.80 m, the pendulum bob has a mechanical energy which is equal to its potential energy, since, its initial kinetic energy is zero. By the time the bob swings to the other end, it has a mechanical energy equal to it initial potential energy since total energy is conserved.
Neglecting friction, the pendulum bob would swing back to its original height of 0.80 m since the total mechanical energy is conserved and at its highest point, it is purely potential energy.
So, the height the pendulum bob swings to after release from a height of 0.80 m neglecting fiction is 0.80 m.
A certain superconducting magnet in the form of a solenoid of length 0.28 m can generate a magnetic field of 7.0 T in its core when its coils carry a current of 80 A. The windings, made of a niobium-titanium alloy, must be cooled to 4.2 K. Find the number of turns in the solenoid.
Answer:
The number of turns in the solenoid is 19506.
Explanation:
Length of solenoid, L = 0.28 m
Magnetic field, B = 7 T
Current, I = 80 A
Let the number of turns is N.
The formula used to find the magnetic field is
[tex]B = \frac{\mu 0N I}{L}\\\\7 = \frac{4 \times 3.14\times 10^{-7}\times N\times 80}{0.28}\\\\N = 19506[/tex]
A person climbs out of swimming pool and stands in the open air.Explain why evaporation of water from the surface of the persons body causes the person to feel cold
Answer:
The person feels cool at first because the swimming pool water is usually cool and he/she has that water on his body. But when it evaporates, the cool air directly touches his body and that's why he/she feels cold.
Thank You! Please mark me Brainliest!
What is the connection of H ions at a ph=2?
Answer:
Explanation:
High concentrations of hydrogen ions yield a low pH (acidic substances), whereas low levels of hydrogen ions result in a high pH (basic substances). The overall concentration of hydrogen ions is inversely related to its pH and can be measured on the pH scale
a motorcycle covers 500 meters in 25 seconds. calculate the average velocity
Vtb xe máy là:
v=s : t= 500 : 25=20(m/s)
Unos amigos de 5 integrantes salen a comer, el primero pide un pollo a la brasa que cuesta S/50.00, el segundo un aeropuerto que cuesta S/28. 50, el tercero se pide una pizza que cuesta S/20,50, el cuarto se pide un tallarín saltado que cuesta a S/10,80 y el quinto un arroz con marisco que cuesta a S/22.00. Uno de ellos paga con tarjeta de crédito de todos ellos, al pagar le incluyen el 5% del uso de tarjeta. ¿Cuánto pagó en total?
Respuesta:
$138.39
Explicación:
Paso 1: Calcular el total que gastaron
El total que gastaron es igual a la suma de los que gastó cada uno.
$50.00 + $28.50 + $20.50 + $10.80 + $22.00 = $131.80
Paso 2: Calcular el 5% de $131.80
$131.80 × 5% = $6.59
Paso 3: Calcular el total que pagó con la tarjeta
A los $131.80 que gastaron debe sumarle los $6.59 por el uso de tarjeta.
$131.80 + $6.59 = $138.39
The heat required to raise 3 kg of copper from 0°C to 10°C raises 1kg of lead from 10°C to 100°C. If the specific heat capacity of copper is 0.095 cal/g°C,find the specific heat capacity of lead.
The specific heat capacity of lead has been determined to be 0.032 cal/g°C.
The specific heat capacity of a substance is the amount of heat required to increase the temperature of its unit mass by 1 Kelvin rise in temperature. There is no phase change during the process. This can be expressed as:
Q = mcT
c = [tex]\frac{Q}{mT}[/tex]
Where c is the specific heat capacity of the substance, Q is the quantity of heat required, m is the mass of the substance and T is its change in temperature.
In the given question, the heat emitted by the copper mass would be absorbed by the lead mass.
So that;
heat emitted by copper = heat absorbed by lead
[tex]m_{c}[/tex] [tex]c_{c}[/tex]([tex]T_{2}[/tex] - [tex]T_{1}[/tex]) = [tex]m_{l}[/tex][tex]c_{l}[/tex]([tex]T_{2}[/tex] - [tex]T_{1}[/tex])
With the given information in the question, the above equation is expressed as:
3 * 0.095 * (10 - 0) = 1 * [tex]c_{l}[/tex]* (100 - 10)
3*0.095*10 = [tex]c_{l}[/tex] * 90
2.85 = [tex]c_{l}[/tex]*90
[tex]c_{l}[/tex] = [tex]\frac{2.85}{90}[/tex]
= 0.031667
[tex]c_{l}[/tex] = 0.032 cal/g°C
Therefore, the specific heat capacity of lead is 0.032 cal/g°C.
For more clarifications, visit: https://brainly.com/question/22991121
1. How much heat energy ( Q ) is required to heat 2.0 kg of copper from 30.0 oC to 80.0 oC?
Answer:
38500
Explanation:
I looked it up so it may be wrong
Define electric current and drift velocity.
Answer:
Current- the flow of free charges, such as electrons and ions
Drift velocity- the average speed at which these charges move
Answer:
An electric current is the stream of changed particals, such as electrons & ions, moving through an electrical conductor.
The average velocity attained bycharged partical ,such as electrons,in a material due to electric fields
1.
"An estimate of the future value of some variable" is the definition of
A. procurement
B. logistics.
C. a forecast.
D. capacity
How long does it take a car travelling at 80 m/s to decelerate to 18 m/s with an acceleration rate of -16m/s?
We know
[tex]\boxed{\sf a=\dfrac{v-u}{t}}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{v-u}{a}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{18-80}{-16}[/tex]
[tex]\\ \sf\longmapsto t=\dfrac{-62}{16}[/tex]
[tex]\\ \sf\longmapsto t=3.8s[/tex]
Please help! Will mark Brainliest.
Answer:
18 Nm
Explanation:
if the correct answer
Define electric current and drift velocity.
Answer:
Explanation: The voltage or potential difference between two points is defined to be the change in ... I = qnAv relates the drift velocity to the current
A motorcycle starts from rest and gains a velocity of 40m/s in 8 seconds. Find (i) acceleration and (ii) distance travelled by the motorcycle.
• Initial velocity (u) = 0 m/s
• Final velocity (v) = 40 m/s
• time (t) = 8s
Acceleration :[tex]\implies \sf a = \dfrac{\Delta v}{ t} \\ [/tex]
[tex]\implies \sf a = \dfrac{v - u}{ t} [/tex]
[tex]\implies \sf a = \dfrac{40 - 0}{ 8} [/tex]
[tex]\implies \sf a = \dfrac{40}{ 8} [/tex]
[tex]\implies \bf a = 5 \: {ms}^{ - 2} [/tex]
• Distance travelled by the motorcycle:[tex] \longrightarrow \sf {v}^{2} - {u}^{2} = 2as \\ [/tex]
[tex]\longrightarrow \sf {(40)}^{2} - {(0)}^{2} = 2 \times5 \times s \\ [/tex]
[tex] \longrightarrow \sf 1600 = 10s[/tex]
[tex]\longrightarrow \sf s = \dfrac{1600}{10} [/tex]
[tex]\longrightarrow \bf s = 160 \: m[/tex]
the value of 1.0004 to the power 1 by 2 using Binomial approximation is
Given:
The given value is [tex](1.0004)^{\frac{1}{2}}[/tex].
To find:
The value of the given expression by using the Binomial approximation.
Explanation:
We have,
[tex](1.0004)^{\frac{1}{2}}[/tex]
It can be written as:
[tex](1.0004)^{\frac{1}{2}}=(1+0.0004)^{\frac{1}{2}}[/tex]
[tex](1.0004)^{\frac{1}{2}}=1+\dfrac{1}{2}\times 0.0004[/tex] [tex][\because (1+x)^n=1+nx][/tex]
[tex](1.0004)^{\frac{1}{2}}=1+0.0002[/tex]
[tex](1.0004)^{\frac{1}{2}}=1.0002[/tex]
Therefore, the approximate value of the given expression is 1.0002.
why a magnetic compass is used to determine the direction.
Answer:
the magnetic compass is used to determine direction because it is one of the most accurate form of magnet as we already know that a freely suspended magnet always faces towards north direction and south direction
A car generator turns at 400 rpm (revolutions per minute) when the engine is idling. It has a rectangular coil with 300 turns of dimensions 5.00 cm by 6.46 cm that rotates in an adjustable magnetic field. What is the field strength needed to produce a 24.0 V peak emf
Answer:
The field strength needed to produce a 24.0 V peak emf is 0.5913 T
Explanation:
From the formula for maximum emf of a generator,
[tex]emf_{max}= NAB\omega[/tex]
∴ [tex]B = \frac{emf_{max} }{NA\omega}[/tex]
Where N is the number of loops
A is cross section of loops
B is magnetic field strength
ω is the angular frequency of loops
From the question, [tex]emf_{max} = 24.0V[/tex]
N = 300 turns
A = l × b ( since it is a rectangular coil)
A = 6.46 cm × 5.00 cm
A = 0.0646 m × 0.05 m
A = 0.00323 m²
ω = 400 rpm = (400/60)×2π rad/s
ω = 41.8879 rad/s
Putting all the parameters into the formula
[tex]B = \frac{emf_{max} }{NA\omega}[/tex]
[tex]B = \frac{24.0}{300\times0.00323\times41.8879}[/tex]
[tex]B = 0.5913T[/tex]
Hence, the field strength needed to produce a 24.0 V peak emf is 0.5913 T
s27253129 ,,, message me please, I can't ask you my homework question in the comments :c
a sphere of diameter 6.0
cm is moulded into a thin wire of diameter 0.2 mm calculate the length of the wire in metres
Answer:
V1 = 4/3 pi R^3 = pi D^3 / 6 D = 2 R volume of sphere
V2 = pi r^2 L = pi d^2 L / 4 volume of wire
V2 / V1 = 1 = 3/2 d^2 L / D^3 since volumes are equal
L = 2/3 D^3 / d^2 = 2/3 * 6^3 / .02^2 = 360,00 cm = 3600 m
An airplane starts from rest and undergoes a uniform acceleration of 10.8 m/s^2 for 16.7 s seconds before leaving the ground. What is its displacement?
Answer:
3012.012m
Explanation:
s=it +1/2(10.8)(16.7)^2
state Pascal's principle of pressure . please help due tomorrow
Answer:
Pascal's law says that pressure applied to an enclosed fluid will be transmitted without a change in magnitude to every point of the fluid and to the walls of the container.
Explanation:
The pressure at any point in the fluid is equal in all directions.
Explanation:
According to pascal law ,Force applied on bulk of water in a container will be distributed to all molecules of water...
Phương trình chuyển động thẳng đều của một chất điểm có dạng: x = 2t – 10. (x: km, t: h). Quãng đường đi được của chất điểm sau 2h là bao nhiêu?
Answer:
Distance cover in 2 hour = 6 kilometer
Explanation:
Given equation:
x = 2t - 10
where
x = kilometer
t = hour
Find:
Distance cover in 2 hour
Computation:
T = 2
So,
x = 2t - 10
x = 2(2) - 10
x = 4 - 10
x = -6
Distance cover in 2 hour = 6 kilometer
Answer:
The distance is 6 km.
Explanation:
The equation of uniform linear motion of a particle has the form: x = 2t – 10. (x: km, t: h). What is the distance traveled by the particle after 2 hours?
x = 2t - 10
distance traveled after t = 2 hours
Substitute t = 2 in the given expression
x = 2 x 2 - 10
x = 4 - 10
x = - 6 km
So, the distance is 6 km.
What did Ernest Rutherford's experiment of a beam of alpha particles aimed
at a sheet of gold foil lead him to conclude?
A. The theory that atoms were the building block of all matter was
correct.
B. The majority of the atom's mass and its positive charge are
concentrated in the atom's center.
C. An electron has a larger mass than the alpha particles, causing
them to reflect upon collision.
D. J.J. Thomson's theory of electrons suspended in a sea of
positively charged particles was correct.
Answer:
B - Only a concentration of mass in the nucleus could explain the deflection of the incident particles.
Question 6 (5 points)
Which of the following scenarios describes a condition in which resonance can
occur?
A) Tivo tuning forks are struck simultaneously, one with a frequency of 659Hz
and one with a frequency of 639 Hz, causing beats.
B Two tuning forks that vibrate at the same frequency are near each other. One
tuning fork is struck with a mallet so that it vibrates.
C) A tuning fork is over a column of air that is 9/2 the wavelength of the wave
produced by the tuning fork.
An isolated tuning fork is struck with a mallet, causing it to vibrate strongly at
659 Hz.
Answer:
B. Two tuning forks that vibrate at the same frequency are near each other. One tuning fork is struck with a mallet so that it vibrates.
Explanation:
A wave can be defined as a disturbance in a medium that progressively transports energy from a source location to another location without the transportation of matter.
In Science, there are two (2) types of wave and these include;
I. Electromagnetic waves: it doesn't require a medium for its propagation and as such can travel through an empty space or vacuum. An example of an electromagnetic wave is light.
II. Mechanical waves: it requires a medium for its propagation and as such can't travel through an empty space or vacuum. An example of a mechanical wave is sound.
An amplitude can be defined as a waveform that's measured from the center line (its origin or equilibrium position) to the bottom of a trough or top of a crest.
Resonance can be defined as a phenomenon in which an object is forced to vibrate as a result of the vibration of a second object at the same natural frequency of the first object. Thus, it's an increase in the amplitude of oscillation that occurs when the frequency of a periodically applied force is equal to the natural frequency of the system on which it's acting.
Hence, the scenario that best describe a condition in which resonance can occur is two tuning forks that vibrate at the same frequency are near each other. One tuning fork is struck with a mallet so that it vibrates.
Answer:
B Two tuning forks that vibrate at the same frequency are near each other. One
tuning fork is struck with a mallet so that it vibrates.
Explanation: hope this helps ;)
