Answer:
The correct answer to the question will be compass i.e compass is not a part of a DC motor. Various parts of a DC motor are coil of wire, armature, field magnets, brushes and commutator. The coil of wire plays a vital role in DC motor.
Explanation:
Using the diagram to the right to answer question # 18. Fig shows a ball fired horizontally from a cannon while simultaneously another is dropped from the same height. Which best describes what happens to these objects?
The one dropped vertically will reach the ground first
The one shot out of the cannon will reach the ground first
They will both reach the ground at the same time
The one shot out of the cannon will keep traveling to the right forever.
what is physical quantity
A physical quantity is a property of a material or system that can be quantified by measurement. A physical quantity can be expressed as the combination of a numerical value and a unit. For example, the physical quantity mass can be quantified as n kg, where n is the numerical value and kg is the unit.
Answer:
a property of a material or system that can be quantified by measurement
have a nice day!!!
Suppose a forklift hoists a container weighing 2670 Netwons up from
ground level, setting it down on aloading dock 4.5 meters above ground
level. How much work was done by the forklift in this maneuver?
Answer:
12,015JoulesExplanation:
Work is said to be done when the force applied to an object cause it to move over a distance.
Workdone = Force * Distance
Given
Force = 2670 N
Distance = 4.5 meters
Substitute the given values
Work done = 2670 * 4.5
Workdone = 12,015Joules
Hence the amount of work done by the forklift is 12,015Joules
The weight of an object at the surface of Earth is 90 N. What is its weight at a distance 2R from the surface of Earth
Answer:
The weight at a distance 2R from the surface of Earth will be [tex]F'=10 N[/tex].
Explanation:
First of all, we need to find the acceleration of gravity at 2R. Using the gravitational force equation
[tex]F=G\frac{mM}{R^{2}}[/tex]
Where:
M is the mass of the earth
m is the mass of the object
G is the gravitational constant
R is the radius of the earth
We can equal the gravitational force with the second Newton's law (F=ma)
[tex]F=G\frac{mM}{R^{2}}[/tex]
[tex]mg=G\frac{mM}{R^{2}}[/tex]
We know the weight at the earth surface is 90 N, which means:
[tex]90=G\frac{mM}{R^{2}}[/tex]
Now, we have the same equation in the case of 2R as a distance from the surface of the object. Let's remember we need to use the distance from the center of the mass of the earth, so in this case, will be 3R.
[tex]F'=G\frac{mM}{(3R)^{2}}[/tex]
[tex]F'=G\frac{mM}{9R^{2}}[/tex]
[tex]F'=\frac{1}{9}G\frac{mM}{R^{2}}[/tex]
Using the above equation we have:
[tex]F'=\frac{1}{9}90[/tex]
[tex]F'=\frac{90}{9}[/tex]
Therefore, the weight at a distance 2R from the surface of Earth will be [tex]F'=10 N[/tex].
I hope it helps you!
A tank is is half full of oil that has a density of 900kg/m3. Find the work W required to pump the oil out of the spout. (Use 9.8 for g and 3.14 for . Round your answer to three significant digits.)
Image of the tank has been attached.
From online sources, we will use radius r = 9 meters with a spout of height h = 3 meters.
Answer:
W = 75800 KJ
Explanation:
Let's assume that we inscribe a cylinder which is x units from the center of the sphere and also has a height denoted by ∆x.
Now, At the center of the sphere with radius r, the equation of the sphere is given as:
x² + y² + z² = r².
Now, at the point location where the cylinder is x units from the center point, the width(y) of the sphere will be gotten as:
0² + y² + x² = 9²
y² + x² = 81
y² = 81 - x²
Thus;
y = √(81 - x²)
So y = r is the radius of the cylinder.
Thus; volume of the cylinder is given as:
V = πr²h
∆V = π(81 - x²)∆x
Integrating, we have;
V = π(81 - x²)
The weight of the water is given as:
F = mg
We know that density is;
ρ = m/V
So, m = ρV
Thus;
F = ρVg
F = (900)[π(81 - x²)](9.8)
F = 8820π(81 - x²)
Work needed to move this water up is;
W = Fd
The water will move up x to units to the center which is 9 units up to the top of the sphere, and 3 units to get to the top of the spout. Thus, d = 9 + 3 + x = 12 + x
Thus;
W = 8820π(81 - x²)(12 + x).
Due to the fact that x varies from -9 to 0 at the bottom half of the sphere, the required work will be;:
W = ∫8820π(81 - x²)(9 + x)dx (from x = -9 to 0)
Using online integral calculator, we have;
W = 8820π × 2733.75
W = 75749.061 KJ
To 3 significant figures = 75800 KJ
A 8.5 kg brick is dropped onto a 6.5 kg toy truck, which is moving across a level floor at 0.50 m/s. With what velocity do the truck and brick continue to move, after the brick has landed on the truck?
Answer:0.2167 m/s
Explanation:
Given
mass of brick M=8.5 kg
mass of toy truck m=6.5 kg
the velocity of truck u=0.5 m/s
Suppose v is the velocity after brick is landed on the truck
There is no external force acting so momentum is conserved
mu=(M+m)v
[tex]v=\dfrac{6.5}{15}\times 0.5\\v=0.2167\ m/s[/tex]
3. A soccer player applies an average force of 180 N during a kick. The kick accelerates a .45 kg soccer ball from rest to a speed of 18 m/s. What is the impulse imparted to the ball
Answer:
8.1Ns
Explanation:
Impulse is expressed as the product of Force and time
Impulse = Ft
F is the force = 180N
Get the time using the equation of motion
v = u+at
18 = 0+F/m(t)
18 = 180/0.45(t)
18 = 400t
t = 18/400 secs
Recall that;
Impulse = Ft
Impulse = 180×18/400
Impulse = 8.1Ns
Hence the impulse imparted to the ball is 8.1Ns
How old is the sun
and when will the sun blow up
Answer:
the sun is 4.5 bill years old. and Astronomers estimate this to be a short 7 billion years from now before its explodes.
Explanation:
The period T of a pendulum of length L is measured to determine g at the surface of Earth. The equation used is T=2π√L/g. The mass of the pendulum bob is 10.0 kg, and the length of the pendulum is 1.00 m. Which of the following would contribute most to the expected error in the result?
a. 10% uncertainty in the measurement of the mass.
b. Approximating the value of t as 3.14.
c. Variation in the value of g as the pendulum bob moves along its arc.
d. Using the average period of 10 timed oscillations instead of the period of 1 timed oscillation.
d. Starting the pendulum swinging by releasing it from a horizontal position D. E.
Answer:
C: Variation in the value of g as the pendulum bob moves along its arc.
Explanation:
The formula for period of a simple pendulum is given by;
T = 2π√(L/g)
Where;
L is length
g is acceleration due to gravity
Now, from this period equation, it is clear that the only thing that can affect the period of a simple pendulum are changes to its length and acceleration due to gravity.
Looking at the options, the only one that talks about either the length or gravity as being potential causes of the error is option C
The dependent variable is always opposite of the independent variable? True or false?
Answer: The dependent variable is always the opposite of the independent variable. False ... Scientific theories are broad explanations that are widely accepted as true.
Explanation:
Equal amounts of heat are added to equal masses of the four substances
listed in the table. All four substances are initially at room temperature. Which
of the substances will have the highest increase in average molecular kinetic
energy?
Substance
air
glass
plastic
wood
Specific heat capacity (kJ/kg•°C)
1.01
0.84
2.60
1.68
A. Glass
B. Air
O O O O
C. Plastic
D. Wood
Answer:
the answe is letter c.plastic
Write down short notes on:
c. Power
Answer: In the International System of Units, the unit of power is the watt, equal to one joule per second. In older works, power is sometimes called activity. Power is a scalar quantity.
Explanation: SI unit: watt (W)
In SI base units: kg⋅m2⋅s−3
Derivations from other quantities: P = E/t; P = F...
If you exert a force of 10.N to lift a box over 1 m how much work do you do?
5
20
10
Answer:
The work done is 10 Joules
Explanation:
Mechanical Work
It is the amount of energy transferred by a force. It's a scalar quantity, with SI units of joules.
Being the force vector and the displacement vector, the work is calculated as:
[tex]W=\vec F\cdot \vec s[/tex]
If both the force and displacement are parallel, then we can use the equivalent scalar formula:
W=F.s
If a force of F=10 N is used to lift a box over a distance of s=1 m, the work done is:
W = 10 N * 1 m
W = 10 J
The work done is 10 Joules
PLEASE HELP ME ASAP
What symbol represents a change in entropy?
A. H
B. AH
C. S
D. AS
The answer is D..................................................
If the column of mercury in a barometer stands at 72.6 cm, what is the atmospheric pressure?
(The density of mercury is 13.6 X 103 kg/m3 and g = 9.80 m/s2)
Answer:pressure = density * acceleration due to gravity * height
H=72.6cm= 0.726m
P=0.726*13.6*10^3*9.8
P=96761.28Pa
Explanation:
The atmospheric pressure if the column of mercury in a barometer stands at 72.6 cm is 9.68 × 10⁴ Pa.
What is Pressure?The stress at a location within a confined fluid or the perpendicular force per unit area are the two definitions of pressure used in the physical sciences. A 42-pound box with an area of 84 square inches at the bottom will apply pressure on a surface equal to the force divided by the surface area.
Given:
The height in the barometer, h = 72.6 cm or 0.726 m,
The density of mercury, d = 13.6 × 10³ kg/m³,
The gravitational acceleration, g = 9.80 m/s²,
Calculate the atmospheric pressure by the following formula,
P = dgh
Here, P is the atmospheric pressure
Substitute the values,
P = 13.6 × 10³ × 9.80 × 0.726
P = 9.68 × 10⁴ Pa,
Therefore, the atmospheric pressure if the column of mercury in a barometer stands at 72.6 cm is 9.68 ×10⁴ Pa.
To know more about Pressure:
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Why are Newton’s 3 laws important?
Answer:
Newton's law are very important because they tie into almost everything we see in everyday life. ... Newton's laws speak very generally all forces, but to use them for any specific problem, you have to actually know all the forces involved, like gravity, friction, and tension.
Measurement is advantageous in daily life. Why?
50 POINTS WILL MARK BRAINLIEST!!!!
Choose a scientist from the timeline on the previous page. Conduct research using outside sources. Be sure to choose reliable resources such as government, scientific, and educational websites. Document all research in your own words. Be sure to properly site all resources used in your assignment.
Research and respond to the following: The person is Neil Bohr
Were there experiences in his life that led to his interest in science and the study of the atom?
Defend his work on the atom and its contribution to the modern atomic model.
Point out which contributions are present in the modern atomic model and which were eventually disproven and thus are not part of the modern model.
Neil Bohr works on atomic model and contributes semi-classical model of an atom.
What is Bohr's model of an atom?Neil Bohr put forth the Bohr model of the atom in 1915. It was created by the modification of Rutherford's atomic model.
By explaining that electrons move in fixed orbitals (shells) and not anywhere in between, Bohr theory amended the atomic structure model. He also showed that each orbit (shell) has a fixed energy. Bohr refined Rutherford's model of the atom's nucleus to include electrons and their varying energy levels.
In Bohr's theory, there is a tiny, positively charged nucleus that is surrounded by negatively charged electrons that orbit the nucleus. According to Bohr, an electron that is farther from the nucleus has more energy than one that is closer to it.
Learn more about of Bohr's atomic model here:
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A playground merry-go-round is a solid disk of radius 2 m and mass 500 kg. If four children with masses of 27 kg each are standing on the edge (holding on), how hard would an AP Physics student have to push tangent to the edge to accelerate the whole thing at 3.1 rad/s^2
Answer:
F = 2220 N
Explanation:
There exists a fixed relationship, that resembles Newton's 2nd Law (applied to rigid bodies) between an external net torque (τ), the rotational inertia (I) of the body, and the angular acceleration (α) due to the torque, as follows:[tex]\tau = I * \alpha (1)[/tex]
By definition, the magnitude of the torque is given by the following expression:τ = F* r* sinθ (2)where F is the applied force, r is the distance to the center of rotation, and θ is the angle between the force and the position vector from the center of rotation to the line of action of the force.In this case, as the force is tangential to the edge, both vectors are perpendicular each other, so (2) becomes simply as follows:τ = F*r (3)Replacing in (1), we have:F*r = I*α (4)I is the total rotational inertia, that is composed by two terms, one is the rotational inertia of the disk, Idisk, which is given by the following expression:[tex]I_{disk} = m*\frac{r^{2} }{2} (5)[/tex]
The other component of I, is due to the four children.Assuming that we can treat them as point masses, the rotational inertia due to any of them is as follows:[tex]I_{child} = m_{child} * r^{2} (6)[/tex]
So, the rotational inertia will be (5) plus (6) times 4 (due to there are 4 children at the same distance r from the center of rotation), as follows:[tex]I_{t} = I_{disk} + 4* I_{child} (7)[/tex]
Replacing by the givens, we get:[tex]I_{t} = \frac{500kg*(2.00m)^{2}}{2} + (4* 27 kg* (2.00m)^{2}) = 1432 kg*m2 (8)[/tex]
Replacing by the values of I, r and α in (4), and solving for F, we get:[tex]F = \frac{I*\alpha }{r} = \frac{1432kg*m2*3.1 rad/sec2}{2.00m} = 2220 N (9)[/tex]
Kinetic energy is the energy of movement describe how kinetic energy plays a role in transferring heat from one object to another
can someone give me a 5 day fitness plan with all the reps and sets for 3 only and 4 exercises a day
Answer:
Classic 5 Day Split
Day 1 – Chest
Day 2 – Legs
Day 3 – Rest
Day 4 – Back
Day 5 – Arms
Day 6 – Shoulders
Day 7 – Rest
Upper Lower Push Pull Legs
Day 1 – Upper
Day 2 – Lower
Day 3 – Rest
Day 4 – Push
Day 5 – Pull
Day 6 – Legs
Day 7 – Rest
5 Day Split Variation
Day 1 – Chest
Day 2 – Legs & Shoulders
Day 3 – Back
Day 4 – Biceps & Triceps
Day 5 – Core & Cardio
Day 6 – Rest
Day 7 – Rest
Explanation:
A ball is dropped from the roof of a building. Points A, B, C, and D in the diagram below represent positions of the ball as it falls. At which position will the ball have the greatest kinetic energy?
Answer:
C. C
Explanation:
The ball will have its greatest kinetic energy just before it touches the ground which is at point C.
Kinetic energy of a body is the energy due to the motion of the body. As a body moves and its speed increases as a result of acceleration, then the kinetic energy will increase more.
As the body starts from rest, at point A, through B and C, the velocity increases drastically due the pull of the earth.
So, point C will show the greatest velocity and hence the most kinetic energy by the body.
Marvin Martian is standing on planet Potatoine.
Potatoine has the following physical data:
Radius: 6.4x106 m
Mass: 2.0x1024 kg
If Marvin's mass is 35 kg, calculate his weight on Potatoine.
Answer:
W = 113.98 N
Explanation:
Given that,
Radius of Potatoine[tex]R=6.4\times 10^6\ m[/tex]
Mass of Potatoine, [tex]M=2\times 10^{24}\ kg[/tex]
Mass of Marvin, m = 35 kg
We need to find his weight on Potatoine. Weight of an object is given by :
W = mg
g is acceleration due to gravity, [tex]g=\dfrac{GM}{R^2}[/tex]
So,
[tex]W=\dfrac{GMm}{R^2}\\\\W=\dfrac{6.67\times 10^{-11}\times 35\times 2\times 10^{24}}{(6.4\times 10^6)^2}\\\\W=113.98\ N[/tex]
So, his weight on Potatoine is 113.98 N.
Question 16 The aerodynamics of a blimp in air are to be tested in a geometrically similar small scale model in a laboratory water tunnel. The model scale is 10:1, the kinematic viscosity of air is 1.46*10-5 m2/s, and the kinematic viscosity of water 1.12*10-6 m2/s. if the prototype is to be tested at a speed of 10 m/s, what speed should the model be tested in water for similitude
jei ghotona i ji ka mandir k bol rahe the j to be a
A tire spinning at 5m/s uniformly accelerates to 10 m/s in five seconds. Its radius is 10 cm. Through what angle will pebble stuck in the tire revolve during this interval?
20 cm and 9 cm 30 cm is the distance for 5 mins so it will be 20 cm
Friction
Questions
1 Jo, Daniel and Helen are pulling a metal ring. Jo pulls with
a force of 100N in one direction and Daniel with a force
of 140 N in the opposite direction. If the ring does not
move, what force does Helen exert if she pulls in the same
direction as Jo?
Answer:
Helen's force must be of 40 N in the same direction as Jo.
Explanation:
Net Force
When a number of forces are applied to an object, the net force is the sum of all the forces considered as vectors.
When all forces act on a straight line, only two possible directions are considered and they can be arbitrarily assigned positive and negative signs.
Jo pulls with a force of 100 N in a direction considered as positive (for example). Daniel applies a force of 140 N in the opposite direction, obviously negative. The net force of these two forces is 100 N - 140 N = - 40 N.
This means there is a resultant non-zero force in the direction of Daniel's. If we are told the net force is zero because of Helen's force, it must be applied in the same direction as Jo's force to balance.
Helen's force must be of 40 N in the same direction as Jo.
Which statement provides the best description of a computational model?
-It is an exact representation of reality, but on a scale we can use more easily.
-It is an individual’s guess about how things will work out.
-It is a simplified version of reality used to make predictions.
-It is something that allows us to know exactly what will happen if we input enough accurate information.
Answer:
The answer is "Option C".
Explanation:
Computation modeling is used as the software for math, physics, or software engineering in the simulation and study of complicated processes. The software framework incorporates many parameters, that characterize the model under study. It is a computer program, in which the mathematical formula is generated by computers and research complex systems.
*Astronomy not physics
How long does it take a message to travel from Earth at Pluto at its average distance from Earth (about 5.9
billion km)?
what are all the kinds of kinematic equations
A cruise ship can accelerate at 0.01 m/s2, if it starts from rest how long does it take
to reach a speed of 25 km/h? How long would it take if it started from a speed of
2.0 m/s?
Answer:
t = 8.24 [min]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f}=v_{o}+a*t[/tex]
where:
Vf = final velocity = 25 [km/h]
Vo = initial velocity = 2 [m/s]
a = acceleration = 0.01 [m/s²]
t = time [s]
Now we must convert the speed from kilometers per hour to meters per second.
[tex]25[\frac{km}{h} ]*[\frac{1h}{3600s}]*[\frac{1000m}{1km} ]=6.94[m/s][/tex]
Now replacing:
[tex]6.94=2+0.01*t\\t=494 [s]\\or\\t=8.24[min][/tex]
