Answer:
0.5 seconds
Explanation:
Work = Fdcos(theta) = 10*2*cos(0) = 20 J
Power = W/t
40 = 20/t
t = 0.5s
Calculate the potential energy of a rock of mass 500 g, held at a height of 2 m above ground.
The potential energy of a rock of mass 500 g, held at a height of 2 m above ground is 9.8J.
The formula for the gravitational potential energy of an object is:
PE = mgh
where m is the mass of the object, g is the acceleration due to gravity (approximately 9.8 m/s^2 on the Earth's surface), and h is the height of the object above the reference point.
So, in this case, we can plug in the given values to find the potential energy of the rock:
PE = (500 g) x (9.8 m/s^2) x (2 m)
The weight of the rock is m*g = 500 g * 9.8 m/s^2 = 4.9 N
Therefore,
PE = 4.9 N x 2 m = 9.8 J
Therefore, the potential energy of a rock of mass 500 g, held at a height of 2 m above ground is 9.8J.
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An astronaut weights 8x10^2
Answer:
800
Explanation:
10^2 = 100
8 x 100 = 800
Sarita Has power of 480 watt. Calculate the amount of mass lifted by her up to 10 Metres in 12 SECONDS?
Answer:
58.7g (answer might differ a little if the answer treats g as 10 instead of 9.81ms-2)
Explanation:
First, apply the formula Energy = Power x Time
Power -> 480W (given)
Time -> 12 seconds (given)
Hence,
Energy = (480 x 12) J (SI units of energy is in Joules, J)
= 5760 J
Since Sarita lifts up the mass, the energy we have calculated above is gravitational potential energy.
That means 5760 J of gravitational potential energy.
Recall that another formula for gravitational potential energy (GPE) is
GPE = mgh (where h is the height lifted, mass is the mass and g is the gravitational constant of 9.81ms-2)
h = 10 metres (given)
Therefore,
5760 = m x 9.81 x 10
98.1m = 5760
m = 58.71559g
Hence, mass lifted is 58.7g (in 3sf)
How long will a boy sitting near the window of a train travelling at 36 km h see a train passing by in the opposite direction with a speed of 18 km h^-1.The length of the slow- moving train is 90 m.
Answer:
5/18 is used to convert km/hr into m/s
1 km = 1000 m
1 hr = 3600 sec
1 km/hr to m/s
1*1000/1*3600
1000/3600metre/sec
10/36metre/sec
5/18 metre/sec
Explanation:
srry if this is wrong!
What causes the poles of the electromagnet in an audio speaker to repeatedly switch directions?
a metal striker that pulls on the magnet
a diaphragm that vibrates around the magnet
a current that rapidly switches direction
a device that opens and closes a circuit
Answer:
he is right its c
Explanation:
Answer:
a current that rapidly switches direction
Explanation:
the work a force does is measured in?
Explanation:
work a force is measured in newton-meters (N-m)
[tex] \huge \hookrightarrow \mathfrak{ \green{Answer}}[/tex]
we know,
[tex] \boxed{ \small{workdone = force \times displacement}}[/tex]
[tex]\longmapsto \: work \: done = N \times m[/tex]
[tex]work \: \: done \: \: is \: \: measured \: \: in \: \: \boxed {\color{gold}{Nm}}[/tex]
Nm = Newton meter
If an object is moving and the sum of all the vector forces on it is zero, then the object will:
accelerate at a constant rate
come to rest
move at a constant speed
none of the previous
If an object is moving and the sum of all the vector forces on it is zero, then the object will move at a constant speed. The correct option is c.
What is vector force?A force's magnitude and direction are both represented by a force vector. This contrasts with expressing the force's magnitude alone, which is known as a scalar quantity.
Typically, a vector is represented by an arrow that points in the direction of the force and has a length proportionate to the strength of the force.
Therefore, the correct option is c, move at a constant speed.
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A student pours a spoonful of dirt into a cup of water. The water and dirt are stirred together. The water turns a light brown color. Some dark pieces float to the top of the cup and another dark layer forms on the bottom of the cup. Which statement BEST describes the contents of the cup?
The statement that is correct is that the contents of the cup form a mixture.
What is the nature of the cup?Though the question is incomplete but I would try to give you a good explanation as much as I can. We must recall that when we talk about a mixture, we have to note that the term mixture would refer to the combination of two or more substances that do not chemically react together.
In this case, we have been told that we have a water that was pure and then we add dirt to it. It is clear that the water and the dirt do not react in any way hence what we have formed is a mixture.
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A flashlight can be made that is powered by the induced current from a magnet moving through a coil of wire. The coil and magnet are inside a plastic tube that can be shaken causing the magnet to move back and forth through the coil. Assume the magnet has a maximum field strength of 0.05 T. Assume that the radius of the coil is 1.5 cm and the magnet is shaken with a frequency of about two shakes per second. Specify the the number of turns necessary to light a standard 1-watt, 3-V flashlight bulb.
Answer:
n = 4.25 x 10⁴ .
Explanation:
EMF required to be produced = 3 V .
Let n be the required no of turns .
rate of change of flux = n x B x A x f where n is no of turns of coil , B is magnetic field , A is area of coil and f is frequency of change .
B = .05 T , A = π x (.015)² = 7.065 x 10⁻⁴ m² , f = 2
emf induced = rate of change of flux
= n x .05 T x 7.065 x 10⁻⁴ m² x 2
= .7065 x 10⁴ x n
Given
.7065 x 10⁻⁴ x n = 3
n = 4.25 x 10⁴ .
which of the following changes will increase the period of an oscillating spring mass system?
a. an increase in the mass on the spring.
b. an increase in the initial displacement of the spring.
c. an increase in the spring constant.
d. more than one of the above.
e. none of the above.
explain your answer. NO LINKS.
Answer:
a. an increase in the mass on the spring.
Explanation:
An increase in the mass on the spring will increase the period of an oscillating spring mass system.
Mathematically, the period of an oscillating spring mass system is given by the formula;
T = 2π √(m/k)
Where;
T is the period.
m is the mass of the spring.
k is the spring constant.
Hence, the mass of a spring is directly proportional to the period of oscillation of the spring.
This ultimately implies that, as the mass of the spring increases, the period of oscillation will increase. Similarly, the period of oscillation will decrease with an increase in the spring constant.
A blue whale with a mass of 1.90 X 10^5 kg was caught in 1947. What is the magnitude of the minimum force needed to move the whale along a horizontal ramp if the coefficient of static friction between the ramp's surface and the whale is 0.460?
The minimum force needed to move the whale along a horizontal ramp, given that the whale has a mass of 1.90×10⁵ Kg is 856520 N
How do I determine the force needed to move the whale?We'll begin by listing out the given parameters from the question. This is shown below:
Mass of whale (m) = 1.90×10⁵ KgCoefficient of static friction (μ) = 0.460Force needed (F) = ?To obtain the force needed to move the whale, we shall first obtain the normal reaction. This is shown below:
Mass of whale (m) = 1.90×10⁵ KgAcceleration due to gravity (g) = 9.8 m/s²Normal reaction (N) = ?N = mg
N = 1.90×10⁵ × 9.8
N = 1862000 N
Finally, we shall determine the force needed. Details below:
Coefficient of static friction (μ) = 0.460Normal reaction (N) = 1862000 NForce needed (F) = ?F = μN
F = μN
F = 0.460 × 1862000
F = 856520 N
Thus, we can conclude that the force needed is 856520 N
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how much energy is needed to evaporate 5 grams of water?
The energy is needed to evaporate 5 grams of water is 1670 kJ.
What is energy?The energy is the ability to do work.
Energy required to change the phase of an object is mass times the latent heat of vaporization.
Q = mL
where, latent heat of vaporization L =334J/g
Given is the mass of water m =5g, then the energy needed will be
Q =5 x 334
Q =1670 kJ
Thus, the energy needed to evaporate water is 1670kJ.
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Until 1979, the world's easiest driving test was administered in Egypt. To pass the test, one needed only to drive about 6 m forward, stop, and drive the same distance in reverse. Suppose that at the end of the 6 m the car's brakes are suddenly applied and the car slides to a stop. If the force required to stop the car is 6.0 X 10^3 N and the coefficient of kinetic friction between the tires and pavement is 0.77, what is the magnitude of the car's normal force? What's the car's mass?
(a) The magnitude of the car's normal force is 7,792.2 N.
(b) The mass of the car is 795.1 kg.
What is the weight of the car?
The weight of the car is calculated by applying Newton's second law of motion as shown below.
Mathematically, the formula for Newton's second law of motion is given as;
Ff = μW
where;
W is the weight of the carμ is the coefficient of kinetic friction between the tires and pavementThe weight of the car is calculated as follows;
W = Ff / μ
W = ( 6,000 N ) / ( 0.77 )
W = 7,792.2 N
Based on Newton's third law of motion, the weight of the car acting downwards is equal to normal force on the car, acting upward.
The mass of the car is calculated as follows;
W = mg
where;
m is the mass of the carg is acceleration due to gravitym = W / g
m = ( 7792.2 ) / (9.8)
m = 795.1 kg
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1) Calculate the time required for a 6,000.-newton
net force to stop a 1,200.-kilogram
traveling at 10. meters per second. Show all
work, including the equation and substitution
with units.
PLEASE HELP!!
I need equation, substitution with units and final answer +explanation. TYSM
According to the given statement The time required is 2 seconds.
What is Force ?An unseen factor is an agent that has the power to alter the resting or moving condition of a body. It has a direction or a magnitude. The stress applied is the location at which force is applied, and the direction where the force applied is known also as direction of the force.
The vector composition of mass (m), acceleration, and the amount of force is used to express force (a). Mathematically, the equation or equation for force may be written as follows:
Force = mass x acceleration.
We know the force and the mass, so we can write:
6,000 N
= (1,200 kg) x (acceleration).
i.e. Acceleration = 6000N/1200kg = 5 m/s² .
That's the acceleration. The speed changes by 5 m/s each second
that the force acts on it. If the force pushes from behind, then it goes
5 m/s per second faster. It moves 5 m/s slower each second if the force is pushing from the front.
We wish to slow it down from its current speed of 10 m/s to 0 m/s. Therefore, the force must push from the front, and the task will be finished in (10/5) = 2 seconds.
So, time required is 2 seconds.
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Chromatic aberration occurs when:___.
a. a mirror does not focus all colors of light to the same place.
b. a lens does not focus all colors of light to the same place.
c. the absorption of blue light by an intervening dust cloud causes a star to look redder than it really is.
d. atmospheric scattering causes the Sun to look red at sunset.
Answer:
b. a lens does not focus all colors of light to the same place.
Explanation:
Chromatic aberration is a defect of a lens. In this defect, the lens is unable to focus the different wavelengths of the light on a single focal point. It is also known as chromatic distortion and color fringing. It is caused by the dispersion of light while passing through a lens. As a result, the image might become blurred and different colors are observed around its edges. It can be corrected by the use of a combination of converging and diverging lenses.
Hence, the correct option will be:
b. a lens does not focus all colors of light to the same place.
Cart A with a mass of 28kg is moving to the RIGHT at 11m/s and Cart B with a mass of 17kg is moving LEFT at negative 9m/s. The carts collide and STICK TOGETHER. What is the velocity of the carts after they collide?
Answer:
Should be 17.8m/s
Explanation:
Initial momentum = Final momentum
(m1×v1)+(m2×v2)=(m1+m2)v since its an inelastic collision.
19. A pitcher throws a baseball toward a batter at 30m/s. The batter swings his
bat and hits the baseball. The baseball flies away in the opposite direction at a
speed of 35m/s. Is there a transfer of energy in this situation? (SC.7.P.11.4)
a) Yes, because both the bat and the ball are moving after the collision.
b) No, because the ball and the bat only touched for a short time.
c) Yes, because the force from the bat changes the motion of the ball
A pitcher throws a baseball towards a batter at 30m/s. The batter swings his bat and hits the baseball, then there is a transfer of energy in this situation : c) Yes, because the force from the bat changes the motion of the ball.
How is energy transferred from baseball bat to a baseball?Although baseball may appear hard and solid, it actually behaves much like a rubber ball. In the fraction of a second that ball collides with the swinging bat, ball compresses as the energy of motion goes into deforming the ball and transforms it into an elastic potential energy.
The collision of baseball with bat is elastic and the collision between baseball and glove is nearly inelastic.
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Excepting a dare to do something physically dangerous is an example of this kind of influence is it (A Direct negative (B Indirect negative (C Direct post ( indirect post
Answer:
a
Explanation:
given that you know the risks it is directly negative
A 2.0-kg laptop sits on the horizontal surface of the seat of a car moving at 8.0 m/s. The driver starts slowing down to stop. Find the minimum stopping distance so the computer does not slip and fall onto the floor if the coefficient of static friction between the seat and the laptop is 0.40 and the coefficient of kinetic friction is 0.20.
Answer: [tex]32.65\ m[/tex]
Explanation:
Given
mass of laptop m=2 kg
The velocity of car u=8 m/s
The coefficient of static friction is [tex]\mu_s=0.4[/tex]
The coefficient of kinetic friction is [tex]\mu_k=0.2[/tex]
As the car is moving, so the coefficient of kinetic friction comes into play
deceleration offered by friction [tex]\mu_kg=0.2\times 9.8\ m/s^2[/tex]
Using the equation of motion [tex]v^2-u^2=2as\\[/tex]
insert the values
[tex]0^2-8^2=2(-0.2\times 9.8)s\\\\s=\dfrac{64}{1.96}\\\\s=32.65\ m[/tex]
A racing car accelerates at the end of the race from a speed of 100
km/h to a speed of 120 km/h in 15 seconds. Find the acceleration
of it in that period of time.
4/3 m/s ( approximately 1.3333... m/s)
A car travels from Kathmandu to Hetauda. The distance covered by it in 4hrs is
200km. Find the average speed of the car.
Answer:
50km/hrs
Explanation:
speed= distance/time.
Differences between diode and transistor
Answer: the diode transforms the alternating current into direct current while the transistor passes the input signals from the low resistance circuit to high resistance circuit.
Explanation:
PLEASE HELP ME URGENT
Here's the solution,
A.) calculate work done :
we know,
[tex]weight \: = mass \times acceleration[/tex]
[tex]weight = 10 \times 10[/tex][tex]weight = 100 \: Newtons[/tex]And,
[tex]work \: done = force \times dispacement[/tex]
[tex]work \: done = 100 \: \times \: 20[/tex][tex]work \: done = 2000 \: joules[/tex]B.) find power :
[tex]power = \dfrac{work \: done}{time} [/tex]
[tex] power = \dfrac{2000}{2} [/tex][tex]power = 1000 \: watt[/tex]Answer:
work done=2000J and power=1000w
Explanation:
(a) Work done= Gravitational potential energy
W=mgh
Data,
m=10kg
h=20m
g=10N/kg
W=10kg*10N/kg*20m
W=2000J or 2kJ
(b). power=work done/time
P=2000/2
P=1000w
draw diagram of how a reflecting telescope works. show how the angles of reflection would work with mirrors placed at 2 different angles
Lenses, which are pieces of curved, clear glass, were employed in early telescopes to focus light.
What is Telescope?Curved mirrors are used by the majority of telescopes nowadays to collect light from the night sky. Light is focused by a telescope's mirror or lens' shape.
Astronomers use a telescope to observe distant things. Curved mirrors are used by the majority of telescopes, including all large telescopes, to collect and concentrate light from the night sky.
The original telescopes employed lenses, which are simply curved pieces of clear glass, to focus light. The "optics" of a telescope are the mirrors or lenses. Strong telescopes may view objects that are extremely faint and incredibly far away.
Therefore, Lenses, which are pieces of curved, clear glass, were employed in early telescopes to focus light.
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Which of the following could be used as an INSULATOR?
a.) plastic plate
b.) silver spoon
c.) copper wire
d.) gold necklace
Answer:
Probably copper wire
Explanation:
I took the class and that's the only one that sounds right but I'm pretty dum lol
Drag and drop the terms at the left to match the appropriate descriptions at the right. ResetHelp Visual acuity Emmetropia Accommodation Astigmatism Myopia Hyperopia Presbyopia Refraction : normal vision. : reduction in visual acuity due to irregularities in the cornea or lens. : farsightedness. : nearsightedness. : age-related farsightedness due to loss of elasticity in the lens. : sharpness of vision. : bending of light rays. : changes the shape of the eye lens to focus light on the retina.
Answer: Visual acuity: sharpness of vision.
Myopia: nearsightedness
Refraction: bending of light rays.
Emmetropia: normal vision.
Accommodation: changes the shape of the eye lens to focus light on the retina.
Presbyopia: age-related farsightedness due to loss of elasticity in the lens.
Astigmatism: reduction in visual acuity due to changes in the cornea or lens.
Hyperopia: farsightedness
Myopia and hyperopia are refractive errors of the eye.
Presbyopia occurs in old age people.
Explanation:
Visual acuity: It can be defined as the inability to observe the details of shape of the object. Person loses sharpness in vision.
Myopia: It is a defect in vision in which person is able to observe the near by objects clearly but not able to see the distant objects.
Refraction: It can be defined as the bending of beam of light when it passes through from one substance to another.
Emmetropia: It is a vision without any defect.
Accommodation: It is the ability of the eye to adjust its focal length and adjusting the light on focus.
Presbyopia: It can be defined as the loss of ability of eye to focus on the object. It occurs in old age.
Astigmatism: It is a refractive error in which the eye does not focus light on retina.
Hyperopia: It is also called as farsightedness. Distant objects can be seen clearly but nearby appears blurry.
If you throw an apple towards the sky why its going up in spite of gravitational pull?
PLS HELP
Answer:
Force
Explanation:
The Force You Put Behind Said Apple Is Greater Than That Of Gravitational Pull
Example : The More Power You Put behind a basketball the higher the basketball will go
Answer:
This could happen because the net force may be acting on only one side.
Explanation:
A crane exerts 56000 Newtons of force over a distance of 4.5 meters. how much power was generated if it took 4.2 seconds to accomplish this?
Answer:
E = F * S definition of energy
P = E / t = F * S / t definition of power
P = 5.6E4 N * 4.5 m / 4.2 s = 60,000 watts
1. At a location in Europe, it is necessary to supply 1000 kW of 60-Hz power. Only power sources available operate at 50 Hz. It is decided to generate the power by means of a motor-generator set consisting of a 20- pole synchronous motor (its electrical rotating frequency is 50 Hz) driving a synchronous generator. How many poles should the synchronous generator have in order to convert 50-Hz power to 60-Hz power
Answer:
Explanation:
From the given information:
The speed of a synchronous motor in relation to its frequency can be represented with the formula:
[tex]n_{sm}= \dfrac{120f_{se}}{P}[/tex]
where,
the electrical frequency [tex]f_{se}[/tex] is measured in Hz
the number of poles = P
For us to estimate the number of poles to have 50 Hz - 60 Hz Power, then we need to relate the frequencies of the above equation.
i.e
[tex]\dfrac{120(50 \ Hz)}{P_1}= \dfrac{120( 60 \Hz)}{P_2} \\ \\ \dfrac{6000 \ Hz}{P_1}= \dfrac{7200 \ Hz}{P_2} \\ \\ \dfrac{P_2}{P_1}=\dfrac{7200}{6000} \\ \\ \\ \dfrac{P_2}{P_1}= \dfrac{12}{10}[/tex]
Thus, we can conclude that 10 poles synchronous motor is attached with 12 poles synchronous generator in order to convert 50 Hz to 60 Hz power.
If a runner has a speed of 8.66m/s and runs for 46.2s what distance is covered? tv = d
v=
d=
t=
Answer:
[tex]\text{Using the formula: }v=\frac{d}{t}\\\therefore vt=d\\\text{Plug and chug:}46.2(8.66)=400.092\text{ metres}[/tex]