The student does zero work on the backpack because the upward force applied by the student is acting perpendicular to the backpack's displacement parallel to the ground.
Use the worked example above to help you solve this problem. An Eskimo returning from a successful fishing trip pulls a sled loaded with salmon. The total mass of the sled and salmon is 50.0 kg, and the Eskimo exerts a force on the sled by pulling on the rope. Suppose the coefficient of kinetic friction between the loaded sled and snow is 0.200.
(a) The Eskimo pulls the sled 5.90 m, exerting a force of 1.10 102 N at an angle of θ = 0°. Find the work done on the sled by friction, and the net work. Wfric = Correct: Your answer is correct. . J Wnet = Correct: Your answer is correct. . J
(b) Repeat the calculation if the applied force is exerted at an angle of θ = 30.0° with the horizontal. Wfric = J Wnet = J
Answer:
(a)
W_friction = 98.1 J
W_net = 550.9 J
(b)
W_friction = 98.1 J
W_net = 463.95 J
Explanation:
(a)
First, we will calculate the work done by friction:
[tex]W_{friction} = \mu R = \mu W = \mu mg\\W_{friction} = (0.2)(50\ kg)(9.81\ m/s^2)\\[/tex]
W_friction = 98.1 J
Now, the work done by Eskimo will be:
[tex]W_{Eskimo} = FdCos\theta\\W_{Eskimo} = (110\ N)(5.9\ m)Cos\ 0^o\\[/tex]
W_Eskimo = 649 J
So, the net work will be:
W_net = W_{Eskimo} - W_{friction}
W_net = 649 J - 98.1 J
W_net = 550.9 J
(b)
First, we will calculate the work done by friction:
[tex]W_{friction} = \mu R = \mu W = \mu mg\\W_{friction} = (0.2)(50\ kg)(9.81\ m/s^2)\\[/tex]
W_friction = 98.1 J
Now, the work done by Eskimo will be:
[tex]W_{Eskimo} = FdCos\theta\\W_{Eskimo} = (110\ N)(5.9\ m)Cos\ 30^o\\[/tex]
W_Eskimo = 562.05 J
So, the net work will be:
W_net = W_{Eskimo} - W_{friction}
W_net = 562.05 J - 98.1 J
W_net = 463.95 J
The mass of the Moon is 7.3x1022 kg and its radius is 1738 km. What is the strength of the gravitational field on the
surface of the Moon? (Do all required steps)
Answer:
1.61 N/kg
Explanation:
Take the universal gravitational constant G as 6.67 × 10^(-11) Nm²/kg²
The required gravitational field strength
= 6.67 × 10^(-11) × 7.3 × 10^(22) / (1738000)²
= 1.61194103 N/kg
= 1.61 N/kg (corr. to 3 sig. fig.)
In one type of mass spectrometer, ions having the same velocity move through a uniform magnetic field. The spectrometer is being used to distinguish 12C and 14C ions. The 12C ions move in a circle of diameter 45.4 cm. Use these atomic mass values: 12C, 12.0 u; 14C, 14.0 u.
Answer:
r = 0.5297 m
Explanation:
In this exercise we use Newton's second law where the force is magnetic
F = ma
centripetal acceleration
a = v² / r
F = q v x B = q v B sin θ
where the angle between the velocity and the magnetic field is 90º, therefore the sin 90 = 1
we substitute
q v B= m v² / r
r = [tex]\frac{m v^2 }{qv B}[/tex]
the mass of each isotope is
12C
m12 = 6 m_proton + 6 m_neutrons
m12 = (6 1,673 +6 1,675) 10⁻²⁷
m12 = 20.088 10-27 kg
14C
m14 = 6 m_proton + 8 m_neutron
m14 = (6 1,673 + 8 1,675) 10-27
m14 = 23,438 10⁻²⁷ kg
in the exercise they indicate that the velocity of the two particles is the same, therefore with the initial data we can calculate the parameters that do not change in the experiment.
[tex]\frac{v}{qB} = \frac{r}{m_{12}}[/tex]
v / qB = 0.454 / 20.088 10⁻²⁷
v / qb = 2.26 10²⁵
this quantity remains constant, let's use the other data to calculate the radius
r = 23.438 10⁻²⁷ 2.26 10²⁵
r = 5.297 10⁻¹ m
r = 0.5297 m
what determines the magnification of an imagev
measure:what the current values of
Answer:
The magnification of an image is equal to the ratio of the image height to the object height.
The optics of your visual system have a total refractive power of about +60 D—about +20 D from the lens in your eye and +40 D from the curved shape of your cornea. Surgical procedures to correct vision generally do not work on the lens; they work to reshape the cornea. In the most common procedure, a laser is used to remove tissue from the center of the cornea, reducing its curvature. This change in shape can correct certain kinds of vision problems.
The length of your eye decreases slightly as you age, making the lens a bit closer to the retina. Suppose a man had his vision surgically corrected at age 30. At age 70, once his eyes had decreased slightly in length, he would be:________.
A. Nearsighted.
B. Farsighted.
C. Neither nearsighted nor farsighted.
Answer:
Farsighted
Explanation:
Farsightedness also known as hypermetropia is caused by the eye being too short(the eye shortens with advancing age) or the crystalline lines not being sufficiently convergent.
A farsighted person can see far objects but can not see nearby objects. His near point is now farther than the 25 cm near point of a normal eye. Images are formed some distance behind the retina.
This eye defect is corrected by the use of a converging lens to reduce the divergence of the rays entering the eye from an object.
A small glider is placed against a compressed spring at the bottom of an air track that slopes upward at an angle of 38.0 ∘ above the horizontal. The glider has mass 9.00×10−2 kg. The spring has 590 N/m and negligible mass. When the spring is released, the glider travels a maximum distance of 1.70 m along the air track before sliding back down. Before reaching this maximum distance, the glider loses contact with the spring.
Required:
a. What distance was the spring originally compressed?
b. When the glider has traveled along the air track 0.80 m from its initial position against the compressed spring, is it still in contact with the spring? What is the kinetic energy of the glider at this point?
Answer:
x = 0.056 m
ΔKE = 0.489 J
Explanation:
Given that
Angle, θ = 38°
Length, L = 1.7 m
Mass, m = 0.09 kg
Spring constant, K = 590 N/m
If we use the Work-Energy theorem, then we know that Potential Energy, PE = Kinetic Energy, KE
This is mathematically written as
1/2kx² = mgH
The height, H we can get by using the relation
H = L.Sinθ
H = 1.7 * Sin 38
H = 1.7 * 0.6157
H = 1.047 m
Next, we use the Work-Energy theorem
1/2kx² = mgH
1/2 * 590 * x² = 0.09 * 9.8 * 1.047
295 * x² = 0.9234
x² = 0.9235 / 295
x² = 0.00313
x = √0.00313
x = 0.056 m
If the spring loses contact at x = 0.056, definitely, it will also lose contact at x = 0.8
Then we use the formula
ΔKE = mg(H - H1)
ΔKE = mg(xsinθ - x2.sinθ)
Where, x = 1.7 , x2 = 0.8
ΔKE = 0.09 * 9.8 (1.7 * sin 38 - 0.8 * sin 38)
ΔKE = 0.882(1.047 - 0.493)
ΔKE = 0.882 * 0.554
ΔKE = 0.489 J
Why does an iceberg have more HEAT than a cup of coffee?
Answer:
The hot coffee has a higher temperature, but not a greater internal energy. Although the iceberg has less internal energy per mass, its enormously greater mass gives it a greater total energy than that in the small cup of coffee.
Explanation:
Answer:
The hot coffee has a higher temperature, but not a greater internal energy. Although the iceberg has less internal energy per mass, its enormously greater mass gives it a greater total energy than that in the small cup of coffee.
We can not hear Infrasound. Why is that?
Answer :
Last choice
Answer:
its frequency is too low
A large box slides across a frictionless surface with a velocity of 12 m/s and a mass of 4
kg, collides with a smaller box with a mass of 2 kg that is stationary. The boxes stick
together. What is the velocity of the two combined masses after collision?
8 m/s
O m/s
12 m/s
4 m/s
us 12:18
Two blocks (with masses of 2.0 kg and 4.0 kg) are on a bench tied together with string. They are being pulled to the right with a force of 30N. They each experience a friction force between the block and the bench.
(Refer to image)
The 2 kg block experiences a friction force with a friction coefficient of 0.30 and the 4 kg experiences a friction with a friction coefficient of 0.20.
Assume that g (the acceleration due to gravity) is 10.0 m/s/s.
Find the magnitude of the friction forces. Find the magnitude of the acceleration of the blocks. Use these answers to help you find the answer to the question:
What is tension in the string connecting the two blocks? (Submit just this answer in Newtons)
Answer:
T = 34/3 N
Explanation:
Magnitude of the friction force on 2kg block = 0.3x10x2 = 6N
Magnitude of the friction force on 4kg block = 0.2x10x4 = 8N
Magnitude of the acceleration of the blocks
F = ma
30 - 8 - 6 = (2+4)a
a = 8/3 m s^-2
Tension in the string connecting the two blocks
Consider the 2kg block,
T - f = ma
T - 6 = 2(8/3)
T = 34/3 N
The gravitational force between two objects with masses 1kg and 28kg separated by a distance 7m is ____________10-11 N.
a.
3.81
b.
26.68
c.
9151.24
d.
1307.32
Hhhhhellllppp fastt
Answer:
a. 3.81
Explanation:
F = GMm/r^2
F = (6.67 x 10^-11 x 28 x 1) / 7^2
F = 3.81 x 10^-11 N
A window air conditioner that consumes 2 kW of electricity when running and has a coefficient of performance of 3 is placed in the middle of a room, and is plugged in. The rate of cooling or heating this air conditioner will provide to the air in the room when running is:
Answer: Q= QH - QL
= W + QL - QL
= W
= 1 kj/8
Explanation:
Since the net rate is positive the room will be heated.
how can you find the mass of a tissue box?
Explanation:
To find the volume of a box of Tissue (also known as a rectangular prism) just multiply the area of the base (length times width) by the height. The formula is V = l• w• h.
Equipotential lines are usually shown in a manner similar to topographical contour lines, in which the difference in the value of consecutive lines is constant. Clear the equipotential lines using the Erase button on the voltage tool. Place the first equipotential line 1 m away from the charge. It should have a value of roughly 9 V. Now, produce several additional equipotential lines, increasing and decreasing by an interval of 3 V (e.g., one with 12 V, one with 15 V, and one with 6 V). Don't worry about getting these exact values. You can be off by a few tenths of a volt. Which statement best describes the distribution of the equipotential lines?
1. The equipotential lines are closer together in regions where the electric field is weaker.
2. The equipotential lines are closer together in regions where the electric field is stronger.
3. The equipotential lines are equally spaced. The distance between each line is the same for all adjacent lines.
Answer:
B or 2
Explanation:
Scientific work is currently under way to determine whether weak oscillating magnetic fields can affect human health. For example, one study found that driv- ers of trains had a higher incidence of blood cancer than other railway workers, possibly due to long expo- sure to mechanical devices in the train engine cab. Consider a magnetic field of magnitude 1.00 3 1023 T, oscillating sinusoidally at 60.0 Hz. If the diameter of a red blood cell is 8.00 mm, determine the maximum emf that can be generated around the perimeter of a cell in this field.
Answer:
fem = 7.58 10⁻⁵ V
Explanation:
For this exercise we use Faraday's law
fem = [tex]- \frac{d \Phi _B}{dt}[/tex]
the magnetic flux is
Ф_B = B. A = B A cos θ
Tje bold are vectros. Suppose the case where the normal to the surface of the red blood cell is parallel to the field, therefore the angle is zero and the cos 0 = 1
The red blood cell area is
A =π r²
indicate that the diameter is r = 8.00 mm = 8.00 10⁻³ m
the magnetic field has a frequency of f=60 Hz, and B₀ = 1.00 10⁻³T, therefore we can write it
B = B₀ sin (wt) = B₀ sin( 2π f t)
we substitute
fem = - A dB / dt
fem = - A B₀ [tex]\frac{ d (sin ( 2\pi f t)}{dt}[/tex]
fem = - π r² Bo (2πf cos 2πft)
the maximum electromotive force occurs when the function is ±1
fem = 2 π² r² B₀ f
let's calculate
fem = 2π² (8.00 10⁻³)² 1.00 10⁻³ 60
fem = 7.58 10⁻⁵ V
A foot spa machine is an electronic gadget used for soaking,bathing and massaging the feet.
Answer:
Just gonna take this at free points and yes you are right but I am confused on what you wanted us to do
which one is odd copper,plastic,rubber
Answer:
It's plastic.
trust me it's plastic, i've rad it somewhere.
All of them have something that's not like the others.
-- Rubber is the only one on the list that has two repeated letters.
-- Plastic is the only one on the list thagt has no repeated letters.
-- Plastic is the only one on the list that has no 'r' in its name.
-- Copper is the only one on the list that is an element, not a compound.
-- Copper is the only good electrical conductor on the list.
-- Plastic is the only one on the list with more than six letters in its name.
-- Rubber is the only one on the list with no 'p' in its name.
-- Plastic is the only one on the list that doesn't end in "-er".
Section of hollow pipe and a solid cylinder have the same radius, mass, and length. They
both rotate about their long central axes with the same angular speed. Which object has the
higher moment of inertia? (a) the hollow pipe (b) the solid cylinder (c) they have the same
rotational kinetic energy (d) impossible to determine
Answer:
Option B (The hollow pipe has the higher angular momentum)Explanation:
Angular momentum = [tex]I*w[/tex]
I = Moment of inertia
w = Angular velocity
Hollow pipe can be considered as hollow cylinder
Moment of Inertia of Hollow cylinder = [tex]Mr^2[/tex]
Moment of Inertia of solid cylinder= [tex]\frac{Mr^2}{2}[/tex]
Clearly Moment of inertia of hollow pipe is greater which states that Angular momentum of it will be greater.
For more information on this visit
https://brainly.com/question/23379286
The lens inside the human eye is convex.
True
False
Answer: True
Explanation: "The lens is a transparent biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina."
What is the acceleration of a 4,000 kg car pushed with a
force of 12,000 N?
Answer:
3 m/s
Explanation:
A= F/m
12,000/ 4000 = 3
Answer:
3 m/s^2
Explanation:
The equation you have to use is F=ma because the problem is a Newton's 2nd law problem.
Our known values are:
F ( Force ) = 12,000 N
m ( mass ) = 4,000 kg
a ( acceleration ) = ?
Now we plug in the known values into the equation and solve
F=ma
12,000=4,000a
We have to divide 4,000 by both sides to isolate the a value
12,000/4,000=4,000/4,000a
The 4,000s on the right of the equation cancel.
And 12,000 divided by 4,000 equals 3
The acceleration (a) is 3 meters per second squared (m/s^2)
Next, check to make sure 3 does work by plugging it back into the equation.
12,000=4,000*3
12,000=12,000 ✔
As you can see, the acceleration will be 3 m/s^2
Unpolarized light with an intensity of (25.0 A) units is passed through two successive polarizing filters, the first with its polarization axis aligned with the vertical and the second with its polarization axis rotated (55.0 B) from the vertical. Find the intensity of the light after passing through the two polarizing filters. Give your answer in same unit as the original light and with 3 significant figures.
Answer:
the intensity of the light after passing through the two polarizing filters is 4.11 units
Explanation:
Given the data in the question;
the intensity of an unpolarized light; I₀ = 25.0 units
when the unpolarized light passes through the first polarizer, its intensity reduces to half of its initial value;
⇒ I₁ = I₀/2 = 25/2 = 12.5 units
the angle between the transmission axes of two polarizers is;
∅ = 55° - 0° = 55°
The intensity of the light after passing through two polarizing filters will be;
I₂ = I₁cos²∅
we substitute
I₂ = 12.5 × cos²(55)
I₂ = 12.5 × 0.3289899
I₂ = 4.11 units
Therefore, the intensity of the light after passing through the two polarizing filters is 4.11 units
someone please help I can mark brainless
What is happening in the graph shown below?
A.
The object moves away from the origin at a speed of 3 m/s, stands still 6 m away from the origin for 3 seconds, then moves toward the origin at a speed of 2 m/s.
B.
The object moves toward the origin at a speed of 3 m/s, stands still 6 m away from the origin for 3 seconds, then moves away from the origin at a speed of 2 m/s.
C.
The object moves toward the origin at a speed of 6 m/s, stands still 6 m away from the origin for 3 seconds, then moves away from the origin at a speed of 8 m/s.
D.
The object moves away from the origin at a speed of 6 m/s, stands still 6 m away from the origin for 3 seconds, then moves toward the origin at a speed of 8 m/s.
Answer:
D. The object moves away from the origin at a speed of 3 m/s, stands still 6 m away from the origin for 3 seconds, then moves toward the origin at a speed of 2 m/s.
Explanation:
I just got it right lol
HELP!!! how does gravity affect how objects fall to the ground
Answer:
c
Explanation:
Answer:
When objects fall to the ground, gravity causes them to accelerate. Acceleration is a change in velocity, and velocity, in turn, is a measure of the speed and direction of motion. Gravity causes an object to fall toward the ground at a faster and faster velocity the longer the object falls.
Explanation:
PLEASE CLICK ON THIS IMAGE I NEED HELP
Answer:
Explanation:
you can say the law of superpoition can tell us that each rock layer is older than the one above it. So, the relative age of the rock or fossil in the rock or fossil in the rock is older if it is farther down in the rock layers. hope it helps
A runner is moving at a speed of 20 m/s. How much distance would they cover in 10 seconds?
Answer:
200 meters
Explanation:
20 x 10 = 200
A cat runs at 2 m/s for 3 s and then slows to a stop with an acceleration of 0.80 m/s2. What is
the cat's displacement during this motion?
A. 6m
B. 2.5 m
C. 8.5 m
D. 4.5 m
20
А
B
D
Answer:
see that the correct one is B
Explanation:
To solve this exercise let us use the kinematic relations
v² = v₀² - 2 a x
as they indicate that the car stops, therefore the final speed is yield v = 0
x = v₀² / 2a
let's calculate
x = 2²/(2 0.8)
x = 2.5 m / s²
When reviewing the answers we see that the correct one is B
Why do you think scientists often find value in looking at and comparing anomalies within data?
Answer:
Anomalies are important because allow us to question if the experiment was carried out properly and if its method can also lead to other observations than the ones stated by the scientist. Anomalies are essential to learn more about a single experiment and improve the way ivestigation is done professionally.
Explanation:
TRUE OR FALSE
2 QUESTIONS
please HELP ASAP
1. false
2. true
I hope this helps ^-^
A block and a ball have the same mass and move with the same initial velocity across a floor and then encounter identical ramps. The block slides without friction and the ball rolls without slipping. 1)Which one makes it furthest up the ramp
Answer:
Both.
Explanation:
Given that a block and a ball have the same mass and move with the same initial velocity across a floor and then encounter identical ramps. The block slides without friction and the ball rolls without slipping. 1)Which one makes it furthest up the ramp ?
Since both of them have the same mass and the same initial velocity, then, they will both have the same kinetic energy.
That is,
K.E = 1/2mv^2
Friction is a force that opposes motion. And since the frictional force is zero,
Both of them will accelerate from Newton's law.
F = ma
We can therefore conclude that both of them will make it further up the ramp.