Answer:
The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of the Planck constant h to be 6.62607015×10−34 when expressed in the unit J⋅s, which is equal to kg⋅m2⋅s−1, where the metre and the second are defined in terms of c and ΔνCs.
Answer:
The kilogram (abbreviation, kg) is the standard international (SI)system of units.it was originally defined as the mass of 1 litre(10-3 cubic meter) of pure water.At the earth's surface ,a mass of 1 kg weight approximately 2.20 pounds (IB)
Explanation:
the force of attraction exerted by the earth on a body of certain mass. It's SI unit is Newton(N).
A child pushes a 100 kg refrigerator with a force of 50 N, but the refrigerator does not move. Suppose the coefficient of static friction between the floor and the refrigerator is 0.4. What is the force due to friction in this scenario
Answer:
50 N
Explanation:
Since the refrigerator doesn’t move, that means the force of friction equals the amount of force the child exerts on the fridge. If the friction force were greater than the force by the child, the fridge would start accelerating towards the child. If it were less than the force the child exerted, the fridge would start accelerating away from the child. Therefore, the net force must be 0, in this case, the friction force is equal to the force the child exerted, for it to stay at rest (as Newton’s First Law stated).
I hope this helps! :)
What type of electric current does a power plant generate for use in your home? OA direct alternating OC. repeating OD straight
Answer:
Direct current
Explanation:
Because it cannot reverse, and it's optimum for usage by electric home appliances.
Unlike Alternating current which reverses, and can cause electric appliances to burn out.
a solid sphere and a hollow sphere having same destiny and radius are rolling down an inclined plane. which one of them will reach first ?
Answer:
The solid sphere.
Explanation:
The moment of inertia for hollow sphere is larger, thereby having a greater resistance to motion. Thus the solid sphere will have greater speed.
Answer:
The solid sphere
Explanation:
So when comparing the spheres, both spheres have the same density and have the same radius which would they are the same size so the only factor to vary them is mass. The solid sphere is filled and thus heavier compared to the hollow sphere which has lighter air. As a result, the solid sphere will be pulled down by gravity more and reach the bottom first.
In raising an object vertically at a constant speed of 2 m / s 10 watts of power is developed the weight of the object is
Answer:
5NExplanation:
Power = Workdone/Time
Since workdone = Force * distance = mgh
Power = mgh/t
Given
Power = 10watts
speed = 2m/s
Power = Weight * velocity
Substitute
10 = Weight * 2
Weight = 10/2
Weight = 5N
Hence the weight of the object is 5N
A bus accelerates forward. If an apple were on the floor of the bus it would move forward.
A: True
B: False
Answer:
False
Explanation:
Since it is on the bus, it would not move forward because the outside acceleration cannot be considered.
Electricity from the local power company costs 5.79 cents/kWh. How much would it cost to run a 120-W stereo system for 4.0 hours per day for 4.0 weeks?
A. $1.33
B. $0.78
C. $0.11
D. $2.18
Answer:
Answer: B. $0.78.
Explanation:
Cost of Electricity
The rate of the cost of electricity is usually expressed in $/kWh or cents/kWh because the consumption of electricity is measured in Kilowatts-hour.
The local power company charges 5.79 cents/kWh.
We are required to calculate the cost to run a 120 W stereo system for 4 hours per day for 4 weeks.
The total consumption time is 4 hours/day * 7 days/week *4 weeks = 112 hours
The total energy consumed is 120 W * 112 h =13,440 Wh.
Converting to kWh: 13,440 Wh/1,000 = 13.440 kWh.
Finally, we multiply by the cost rate: 5.79 cents/kWh * 13.440 kWh = 77.8 cents/100 = $0.78.
Answer: B. $0.78.
Which of the following best describes reflection?
a. Reflection is when waves bend around an obstacle.
b. Reflection is when waves bounce off a surface.
c. Reflection is when waves bend.
Reflection is when waves bounce off a surface this because I did it in 7th grade was my favorite unit to learn in school.
What is Reflection?When two different media come together at an a wavefront might change direction so that it returns to the first medium, which is known as reflection.
The reflection of light, sound, and water waves are typical examples. According to the law of reflection, the angle at which the wave incident on the surface equals the angle at which it is reflected for specular reflection (such as at a mirror).
Reflection produces echoes in acoustics and is used in sonar. It is crucial to the study of seismic waves in geology. Surface waves in bodies of water are used to observe reflection.
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A pinball bangs against a bumper of a pinball machine with a speed of 0.46 m/s. If the ball has a mass of 0.058 kg, what is the ball's kinetic energy?
This needs to be done in 3 mins
Answer:
Okay I might be wrong and sorry if i am either its 12 or 0.402
Explanation:
* I recommend the second one cause its more logical
Be aware I might be wrong
A ball is thrown horizontally at a speed of 24 meters per second from the top of a cliff. If the ball hits the ground 4.0 seconds later, approximately how high is the cliff? I NEED HELP FOR THIS QUIZ LOL
Answer:
78.4m
Explanation:
In these situations, vertical and horizontal components need to be considered separately;
So, horizontal speed is irrelevant since we are talking about vertical height, i.e. the height of the cliff;
But, the fact that the speed is horizontal is relevant because this means the vertical speed initially is 0m/s;
The downwards movement of the ball is due to gravity, which is 9.8m/s²;
The time is given as 4.0s from the top of the cliff to the bottom;
We know the acceleration, time and initial speed so we can use this kinematic equation to solve for distance:
s = ut + ¹/₂at²
s = displacement (/distance)
u = initial vertical velocity = 0
t = time (time taken for the ball to fall) = 4
a = acceleration (downwards) = 9.8
Substitute these values into the equation to get the distance:
s = 0(4) + ¹/₂(9.8)(4)²
s = 78.4m
A washing machine is being dragged with a starting force of 380.8 N to the West, but this is reduced by friction. If the mass of the washing machine is 37 kg
and the coefficient of friction is 0.54, what was the Net acceleration experienced by the washing machine?
A 10.27 m/s^2 South
B 5 m/s^2 South
C 19.01 m/s^2 South
D 7.6 m/s^2 South
Answer:
B. [tex]5\,\frac{m}{s^{2}}[/tex] South
Explanation:
The correct statement is:
A washing machine is being dragged with a starting force of 380.8 N to the South, but this is reduced by friction. If the mass of the washing machine is 37 kg and the coefficient of friction is 0.54, what was the Net acceleration experienced by the washing machine?
The net force of the washing machine moving on the horizontal ground is equal to the external force minus the friction force, where the normal force from the ground on the washing machine is equal to its weight. The free body diagram of the washing machine is presented below. The equation of equilibrium associated with the acceleration of the washing machine is:
[tex]\Sigma F = P -\mu_{k}\cdot m \cdot g = m\cdot a[/tex] (1)
Where:
[tex]P[/tex] - External force exerted on the washing machine, measured in newtons.
[tex]\mu_{k}[/tex] - Kinetic coefficient of friction, dimensionless.
[tex]m[/tex] - Mass, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]a[/tex] - Net acceleration of the washing machine.
If we know that [tex]P = 380.8\,N[/tex], [tex]m = 37\,kg[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]\mu_{k} = 0.54[/tex], then the net acceleration experienced by the washing machine is:
[tex]a = \frac{P}{m}-\mu_{k}\cdot g[/tex]
[tex]a = \frac{380.8\,N}{37\,kg}-(0.54)\cdot \left(9.807\,\frac{m}{s^{2}} \right)[/tex]
[tex]a = 4.996\,\frac{m}{s^{2}}[/tex]
The correct answer is B.
A mosquito can fly with a speed of 1.10 m/s with respect to the air. Suppose a mosquito flies east at this speed across a swamp. The mosquito is flying into a breeze that has a velocity of 1.4 m/s with respect to Earth and moves in the direction of 35 west of south. What is the mosquito's speed with respect to the Earth?
Answer:
The velocity of Mosquito with respect to earth will be 0.302m/s
Explanation:
V(ma) = 1.10 m/s, east Velocity of mosquito with respect to air
V(ae) = 1.4 m/s at 35° Velocity of air with respect to Earth in west of south direction.
Velocity of Mosquito with respect to earth will be
V(me) = V(ma) + V(ae)
We need to find the mosquito’s speed with respect to Earth in the x direction.
V(x, me) = V(x, ma) + V(x, ae) = V(ma) + V(ae)(cos theta(ae) )
Angle (ae) = –90.0° − 35°=−125°
V(x, me) = 1.10 + (1.4)Cos(-125)
= 1.10 + 1.4(-0.57)
= 1.10 -0.798
= 0.302
So the velocity of Mosquito with respect to earth will be 0.302m/s
Question 5 of 10
Why are magnetic materials attracted to magnets?
A. They become permanent magnets when they are in a magnetic
field,
B. They become temporary magnets when they are in a magnetic
field.
C. They are temporary magnets whether or not they are in a magnetic
field.
D. They are also attracted to Earth's magnetic field, which is always
present
Answer:
The answer is B
Explanation:
Trust
Under what circumstances will the projectile have the greatest velocity when it hits the ground? Explain please
25 points and i will give brainliest +5 star rating to a correct a correct answer!!!!
Green light (520 nm) enters glass with n = 1.52. What is speed of light in the glass?
Answer:
1.97 * 10^8 m/s
Explanation:
Given that:
n = 1.52
Recall : speed of light (c) = 3 * 10^8 m/s
Speed (v) of light in glass:
v = speed of light / n
v = (3 * 10^8) / 1.52
v = 1.9736 * 10^8
Hence, speed of light in glass :
v = 1.97 * 10^8 m/s
Two identical peaches, Peach 1 and Peach 2, fall from a cliff at time t=0t=0t, equals, 0 from the same height. Peach 1 is dropped from rest, while Peach 2 is thrown horizontally.
Which graph best describes the vertical displacement of Peach 1 and 2 over time?
Assume the origin of the coordinate system to be the cliff edge.
Choose 1 answer:
Choose 1 answer:
(Choice A)
A
A graph is shown with the vertical axis labeled y and the horizontal axis labeled t. Two lines both start at the origin and slope downwards to the right. The solid line is straight while the dashed line has downward concavity.
(Choice B)
B
A graph is shown with the vertical axis labeled y and the horizontal axis labeled t. Two lines both start at the origin and slope downwards to the right. The dashed line is straight while the solid line has upward concavity.
(Choice C)
C
A graph is shown with the vertical axis labeled y and the horizontal axis labeled t. Two lines both start at the origin and slope downwards to the right with downward concavity. Both lines are coincident.
(Choice D)
D
A graph is shown with the vertical axis labeled y and the horizontal axis labeled t. Two lines both start at the origin and slope downwards to the right with downward concavity. The solid line is shallower than the dashed line.
(Choice E)
E
A graph is shown with the vertical axis labeled y and the horizontal axis labeled t. Two lines both start at the origin and slope downwards to the right with upward concavity. The dashed line is shallower than the solid line.
Report a problem
4 of 9
Answer: The correct answer is graph A.
Explanation:
See Khan Academy.
Answer: it C
Explanation:
State three uses of dimensions.
Explanation:
answers.................
Explanation:
dimension are used for
1 we check the homogeneity of a physical equation
2 drive a possible formula for a physical problem
3 To find dimensions of physical constants or coefficients.
Any force that resists motion and causes heat
Answer: Two objects sliding against each other.
Explanation:
The friction between the two surfaces converts kinetic energy into heat.
Please answer ASAP!!!! Which statement describes the factors that affect the force of a spring?
A. The spring force depends on the spring constant, and increases as displacement
increases
B. The spring force only depends on the spring constant
C. The spring force gets weaker as displacement increases, and is in the same
direction as the displacement
D. The spring force depends on gravity and friction
Answer:
d
Explanation:
the spring depends on gravity and friction
How high can a 40 N force move a load, when 395 J of work is done? (Show work)
A 40 N force would move a load 9.875 m high when 395 J of work is done on the load.
What is work done?The total amount of energy transferred when a force is applied to move an object through some distance
The work done is the multiplication of applied force with displacement.
The SI unit of work done by an object is Joules.
IJ is the work done when a force of 1 N displaces an object by 1 m .
Work Done = Force * Displacement
For the given problem Force =40N and work done = 395 J
By using the above formula
Work Done = Force * Displacement
395 j = 40 N × height
height =9.875 m
Thus a 40 N force supported by a work done of 395 J moves the load up to 9.875 m height
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Which of the following does not illustrate a complete circuit?
Answer:
I think A
Explanation:
because it dosn't have enough tools
A runner exerts a net force of 335 n to accelerate at a rate of 2.5 m/s what is the runners mass
The main difference between distance and displacement is tat
Answer:
Distance is the length of the path taken by an object whereas displacement is the simply the distance between where the object started and where it ended up.
Explanation:
Hope this helps! Good Luck on the rest of your assignments! :)
Answer:
Distance is quite literally the total amount of distance you have covered. Displacement is the total displacement from your origin. For example, if you were to move 5m north then 2m south, your total displacement from your origin would be 3m north.
In a place covered by shadow of cloud sun cannot be seen . Explain with reasons .
Answer:
Because even though our eyes have a huge dynamic range (ability to pick out details in sharply lit and lesser lit areas simultaneously) than any camera, there's a limit.
When there's strong sunlight, your pupils contract and let less light in, which makes the shadows look darker.
When it's cloudy, your pupils widen and let more light in, which makes the shadows look less dark.
Do some experiments with a camera and you'll soon get the hang of it.
NOTE: Also test HDR (high dynamic range) photography, where the camera takes three or more pictures in quick succession, with different exposure settings, and combines them to get the most detail of both bright and dark areas. The result is more or less what we percieve.
A car traveling with 500,000 J of kinetic energy is brought to a kinetic energy of
100,000 J in 12 seconds. What is the force acting on the car to accomplish this?
A:41,666.67
B:3x10^-5N
C:33,333.33N
D:8,333.33N
Answer:
33,333.33 N
Explanation:
Given that :
Initial kinetic energy = 500,000 J
Final kinetic energy = 100,000 J
Using the relation :
Force * time = change in momentum (Newton's law)
Force (F) * 0.12 = (500,000 - 100,000)
0.12F = 400,000 J
Force = (400,000 J) / 0.12s
Force = 33333.333
Force = 33,333.33 N
A merry go round exerts a force of 1000 N on a rider on the
outer ring of animals when it takes 15 seconds to make a
complete revolution. If the person weighs 750 N, the radius
of the circle he is making is m. Round your answer to
the nearest tenth.
Answer:
The radius of the circle made by the person on the merry go round is 74.55 meters
Explanation:
The given parameters are;
The force the merry go round exerts on the rider = 1000 N
The time it takes the merry go round to make one complete revolution = 15 seconds
The weight of the person = 750 N
The radius of the circle made by the person on the merry go round = r
We have;
[tex]F_c = \dfrac{m \cdot v^2}{r} = m \cdot \omega ^2 \cdot r[/tex]
Where;
m = The mass of the person
v = The velocity of the person
[tex]F_c[/tex] = The centrifugal force acting on the person = 1,000 N
r = The radius of the circle made by the person on the merry go round
ω = Angular velocity = 2·π/15 rad/s
We have;
The mass of the person = The weight/(The acceleration due to gravity, g)
∴ The mass of the person = 750/9.81 ≈ 76.45 kg
By substituting the calculated and known values into the equation for the centripetal force, we have;
[tex]F_c[/tex] = m × ω² × r
1000 = 76.45 × (2·π/15)² × r
r = 1000/(76.45 × (2·π/15)²) = 74.55 m
The radius of the circle made by the person on the merry go round = r = 74.55 m.
plzzzz help me will mark u brainiest
Answer:
D
Explanation:
A block and tackle consisting of 5 pulleys is used to raised a load of 400N through a height of 10m.If the work done against friction is 100j.
Calculate;
1)The work done by the effort
2)The efficiency of the system
3)The effort applied
Answer:
1) 4000Joules
2) 25%
3) 320N
Explanation:
A block and tackle consisting of 5 pulleys is used to raised a load of 400N through a height of 10m.If the work done against friction is 100j.
Calculate;
1)The work done by the effort
2)The efficiency of the system
3)The effort applied
1) Workdone by the effort is the work input = Load * distance moved by the Load
Workdone by the effort = 400 * 10
Workdone by the effort = 4000Joules
2) Efficiency = Work output/Work input * 100
Work output = work done against friction = 100 Joules
Efficiency = 100/4000 * 100
Efficiency = 10000/4000
Efficiency = 25%
Hence the Efficiency of the system is 25%
3) Using the efficiency formula:
efficiency = MA/VR * 100
Velocity ratio = 5
MA = Load/Effort
efficiency = (L/E)/5 * 100
25 = 400/E/5 * 100
25/100 = 400/5E
0.25 = 400/5E
0.25 * 5E = 400
1.25E = 400
E = 400/1.25
E = 320N
hence the effort applies is 320N
Two balloons are charged with an identical quantity and type of charge: -0.0025 C. They are held apart at a separation distance of 8 m. Determine the magnitude of the electrical force of repulsion between them.
Answer:
F = 878.9 N
Explanation:
The electrostatic force of attraction or repulsion is given by Coulomb's Law as follows:
F = kq₁q₂/r²
where,
F = Force pf repulsion between balloons = ?
k = Coulomb's Constant = 9 x 10⁹ N.m²/C²
q₁ = q₂ = magnitudes of 1st and 2nd charge = 0.0025 C
r = distance between balloons = 8 m
Therefore,
F = (9 x 10⁹ N.m²/C²)(0.0025 C)(0.0025 C)/(8 m)²
F = 878.9 N
The magnitude of the electrical force of repulsion between them is F = 878.9 N
Calculation of the magnitude of the electrical force:
Here we use Coulomb's Law
F = kq₁q₂/r²
Here,
F = Force of repulsion
k = Coulomb's Constant = 9 x 10⁹ N.m²/C²
q₁ = q₂ = magnitudes of 1st and 2nd charge = 0.0025 C
r = distance between balloons = 8 m
So,
F = (9 x 10⁹ N.m²/C²)(0.0025 C)(0.0025 C)/(8 m)²
F = 878.9 N
Hence, The magnitude of the electrical force of repulsion between them is F = 878.9 N
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How cold is it in texas rn?
Answer:
cold
Explanation:
Which statement best explains why Earth’s outer core is in liquid form? The iron-nickel alloy melts due to hot temperatures. The outer core has a tarry consistency. This region is less dense when compared to the mantle. This region is under extreme pressure from the weight of other layers.
Answer:
I took the science quiz and Its A
Explanation:
HOPE THIS HELPS!
The iron-nickel alloy melts due to hot temperatures. This statement best explains why Earth’s outer core is in liquid form
Where is the outer core?The Earth's outer core is the second innermost layer, located between the inner core and the mantle. It contains mostly iron and nickel, which- due to lower pressure than existing at the inner core- are in the liquid form. The outer core, about 2,200 kilometers (1,367 miles) thick, is mostly composed of liquid iron and nickel because of the high temperature. However, the intense pressure, which increases towards the inner core, dramatically changes the melting point of the nickel–iron, making it solid. The iron and nickel alloy of the outer core is very hot, between 4,500° and 5,500° Celsius (8,132° and 9,932° Fahrenheit).
The outer core is a liquid alloy of mainly iron and nickel. The reason why the core is metal is that the heavy metals sank to the center while the Earth was cooling. The mantle which lies above the core is made of molten rock
correct option is a) The iron-nickel alloy melts due to hot temperatures.
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