Steel beams are used for load bearing supports in a building. Each beam is 4.0 m long with a cross-sectional area of 7.5 10-3 m2 and supports a load of 4.5 104 N. Young's modulus for steel is 210 ✕ 109 N/m2.
A 41.0-kg crate, starting from rest, is pulled across level floor with a constant horizontal force of 135 N. For the first 15.0 m the floor is essentially frictionless, whereas for the next 12.0 m the coefficient of kinetic friction is 0.320. (a) Calculate the work done by all the forces acting on the crate, during the entire 27.0 m path. (b) Calculate the total work done by all the forces. (c) Calculate the final speed of the crate after being pulled these 27.0 m.
Answer:
Explanation:
From the information given;
mass of the crate m = 41 kg
constant horizontal force = 135 N
where;
[tex]s_1 = 15.0 \ m \\ \\ s_2 = 12.0 \ m[/tex]
coefficient of kinetic friction [tex]u_k[/tex] = 0.28
a)
To start with the work done by the applied force [tex](W_f)[/tex]
[tex]W_F = F\times (s_1 +s_2) \times cos(0) \ J[/tex]
[tex]W_F = 135 \times (12 +15) \times cos(0) \ J \\ \\ W_F = (135 \times 37 )J \\ \\ W_F =4995 \ J[/tex]
Work done by friction:
[tex]W_{ff} = -\mu\_k\times m \times g \times s_2 \\ \\ W_{ff} = -0.320 \times 41 \times 9.81 \times 12 \ J \\ \\ W_{ff} = -1544.49 \ J[/tex]
Work done by gravity:
[tex]W_g = mg \times (s_1+s_2) \times cos (90)} \ J \\ \\ W_g = 0 \ j[/tex]
Work done by normal force;
[tex]W_n = N \times (s_1 + s_2) \times cos (90) \ J[/tex]
[tex]W_n = 0 \ J[/tex]
b)
total work by all forces:
[tex]W = F \times (s_1 + s_2) + \mu_k \times m \times g \times s_2 \times 180 \\ \\ W = 135 \times (15+12) \ J - 0.320 \times 41 \times 9.81 \times 12[/tex]
W = 2100.5 J
c) By applying the work-energy theorem;
total work done = ΔK.E
[tex]W = \dfrac{1}{2}\times m \times (v^2 - u^2)[/tex]
[tex]2100.5 = 0.5 \times 41 \times v^2[/tex]
[tex]v^2 = \dfrac{2100.5}{ 0.5 \times 41 }[/tex]
[tex]v^2 = 102.46 \\ \\ v = \sqrt{102.46} \\ \\ \mathbf{v = 10.1 \ m/s}[/tex]
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
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.
a boy standing by a lake sees a fish in the pond and tries to thrust a spear into it he will success or not explain with reason
He will not probably success to thrust a spear into the fish in the pond because when light travels from water to air , it bends due to refractive property of light.
What is refraction of light?Refraction is the bending of a wave as it travels through different media. The two materials' different densities are what lead to the bending.
Refraction is defined as "the change in a wave's direction as it passes through a medium."
Although light refraction is one of the most frequently seen phenomena, refraction can also occur with sound and water waves. We can use optical tools like lenses, prisms, and magnifying glasses thanks to refraction. We can focus light on our retina because of the refraction of light, which is another benefit.
When light travels from water to air , it bends due to refractive property of light. So, he e will not probably success to thrust a spear into the fish.
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Can two waves have the
same wavelength but different amplitudes?
Explain
Answer:
I think Yes because they could have different amounts of energy.
Explanation:
PLEASE HELP The United States spends over $20 billion a year on space exploration through NASA. Do you think that this has been worth the cost? In three to five sentences, provide two specific examples of things we have learned from space exploration, and explain how these examples influence your opinion.(4 points)
Answer: I think $20 billion a year it’s worth the cost. The reasoning behind that is because we can conduct research on various things that could help out humanity. Therefore we can conclude that’s spending billions of dollars every year is worth it.
Explanation:
The average mean distance of Saturn from the sun is
Answer:
From an average distance of 886 million miles (1.4 billion kilometers), Saturn is 9.5 astronomical units away from the Sun. One astronomical unit (abbreviated as AU), is the distance from the Sun to Earth. From this distance, it takes sunlight 80 minutes to travel from the Sun to Saturn.
we have that from the Question"The average mean distance of Saturn from the sun is" it can be said that Tthe average mean distance of Saturn from the sun is
A distance of 1427 x 10^6 km or 886 696 691 milesFrom the Question we are told
The average mean distance of Saturn from the sun is
Generally
The Sun is the star of the milky way galaxy and its distance from every planet in the milky way determines in one way or another its properties and in-habitability
Saturn being a Planet of the milky way we see that Saturn is a significant distance away from sun
A distance of 1427 x 10^6 km or 886 696 691 miles
Therefore
The average mean distance of Saturn from the sun is
A distance of 1427 x 10^6 km or 886 696 691 miles
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(will give brainliest to whoever is first and gives reason) A mass is spun in a circle with a frequency of 40Hz. What is the period of its rotation?
Answer:
[tex]\huge\boxed{T = 0.025\ seconds}[/tex]
Explanation:
Given:
Frequency = f = 40 Hz
Required:
Time period = T = ?
Formula:
[tex]\sf T = 1 / f[/tex]
Solution:
T = 1 / 40
T = 0.025 seconds
[tex]\rule[225]{225}{2}[/tex]
Hope this helped!
~AH1807How fast were both runners traveling after 4 seconds?
40
Distance (in yards)
30
20
10
1
2.
3
0
Time in seconds
Answer:
they were fast ⛷⛷
[4] A tortoise and a hare cover the same distance in a race. The hare goes very fast but stops frequently while the tortoise has a steady pace and finish first
Answer:
I know that story where the hare sleeps
TRUE OR FALSE
2 QUESTIONS
NEED HELP ASAP
THX :)
LOTS OF POINTS :>
Answer: Both False
Explanation:
Our Milky Way Galaxy is a spiral galaxy. Some spiral galaxies are what we call "barred spirals" because the central bulge looks elongated
Irregualuar glaxyices are all over the place
A projectile is fired with an initial velocity of 120.0 m/s at an angle, θ, above the horizontal. If the projectile’s initial horizontal speed is 55 meters per second, then angle θ measures approximately
Answer:
algm sabe tô precisando muito
Q1 what is the direction of current?
Answer:
the external circuit is directed away from the positive terminal and toward the negative terminal of the battery
You can hear sounds transmitted through alr, water, or steel but not through the empty vacuum of space. What type of wave carries sound?
gravity
light
mechanical
electromagnetic
Which of these statements best explains why the atmosphere of today was partly due to the interactions of spheres in the past?
Bacteria used nutrients in the soil for volcanic eruptions.
Chemicals released from water formed the atmosphere.
The molten Earth released hydrogen and helium into the atmosphere.
The increase in fertility of soil around the volcano helped produce rain.
Answer:
The answer is: Plants and animals exchange carbon dioxide and oxygen with the atmosphere.
Explanation:
Got the answer right.
how can we minimise the use of plastic
Answer:
recyclable toothbrushes, cardboard or metal straws, cardboard gallons instead of plastic, use glass and reusable cups
Explanation:
A ball is sitting at the top of a ramp. As the ball rolls down the ramp, the potential energy of the ball decreases, what happens to the potential energy as the ball moves
Answer:
the potential energy decreases as it is converted to kinetic energy.
Explanation:
As things move, their potential energy converts to kinetic energy to power them along. When a ball rolls down the top of a ramp, all the potential energy it accumulated at the top of the ramp converts to kinetic energy to help it roll down. In other words, its potential energy decreases as its kinetic energy increases.
A class is learning about states of matter. The students set up the investigation in the diagram.
Which kinds of energy are needed in this investigation to change the state of matter of the owl made of wax?
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.
In a test of an energy-absorbing bumper, a 2800-lb car is driven into a barrier at 5 mi/h. The duration of the impact is 0.4 seconds. When the car rebounds from the barrier [in the opposite direction], the magnitude of its velocity is 1.5 mi/h. Use the principle of impulse and momentum to determine the magnitude of the average horizontal force (lb) exerted on the car during the impact.
Answer:
F = 2074.13 lb
Explanation:
Given that,
Mass of car, m = 2800 lb = 1270.059 kg
Initial speed, u = 5 mi/h = 2.2352 m/s
Final speed, v = - 1.5 mi/h = -0.67056 m/s (in opposite direction)
Time, t = 0.4 s
We need to find the magnitude of the average horizontal force (lb) exerted on the car during the impact. It can be calculated as :
[tex]F=m\times \dfrac{v-u}{t}\\\\F=1270.059\times \dfrac{-0.67056 -2.2352 }{0.4}\\\\F=9226.21\ N[/tex]
or
F = -2074.13 lb
So, the required force is 2074.13 lb.
Water enter the horizontal, circular cross-sectional, sudden-contraction nozzle sketched below at section (1) with a uniformly distributed velocity of 30 ft/s and a pressure of 80 psi. The water exits from the nozzle into the atmosphere at section (2) where the uniformly distributed velocity is 100 ft/s. Determinethe axial component of the anchoring force required to hold the contraction in place.
This question is incomplete, the missing image is uploaded along this answer.
Answer:
the axial component of the anchoring force required to hold the contraction in place is 365.6 lb
Explanation:
Given the data in the question and as illustrated in the image below;
first we calculate the area at section 1
A₁ = (πD²)/4
we substitute
A₁ = (π(3 in)²)/4
A₁ = 7.06858 in²
we know that; 1 ft = 12 in
A₁ = ( 7.06858 / (12²) ) ft²
A₁ = ( 7.06858 / 144 ) ft²
A₁ = 0.0491 ft²
now, we write the elation for area at section 2
A₂ = πd²/4
here, d is the diameter at section 2
next, we use the conservation of mass equation between the two section;
m" = pV₁A₁ = pV₂A₂
we calculate the mass flow rate;
m" = pV₁A₁
= (1.94[tex]\frac{slug}{ft^2}[/tex]) × 30[tex]\frac{ft}{s}[/tex] × 0.0491 ft²
= 2.8576 slug/s
Now, Apply the linear momentum along the horizontal direction for the control volume between 1 - 2
-pV₁A₁V₁ = pV₂A₂V₂ = P₁A₁ - F[tex]_A[/tex] - P₂A₂
m"( V₂ - V₁ ) = P₁A₁ - F[tex]_A[/tex] - P₂A₂
F[tex]_A[/tex] = P₁A₁ - P₂A₂ - m"( V₂ - V₁ )
we substitute
F[tex]_A[/tex] = ((80×[tex]\frac{144 in^2}{1 ft^2}[/tex])×0.0491 ft²) - (0×(πd²/4)) - 2.8576( 100 - 30 )ft/s
F[tex]_A[/tex] = 565.632 - 0 - 200.032
F[tex]_A[/tex] = 565.632 - 200.032
F[tex]_A[/tex] = 365.6 lb
Therefore, the axial component of the anchoring force required to hold the contraction in place is 365.6 lb
5.
2075 Set A Q.No. 20 2070 Supp. Set B Q.No. 2 B What
happens to the kinetic energy of photo electrons when
intensity of light is doubled?
[2]
Answer:
The energy of each photon can be transformed into kinetic energy and as this energy does not change, the energy of both photoelectrons remains constant,
Explanation:
The photoelectric effect was explained by Einstein, who assumed that the lz is made up of particles called photons each of a given energy, therefore the photoelectric effect can be explained as a collision of particles.
From this explanation we see that the intensity is proportional to the number of existing particles, when we double the intensity we double the number of particles, but the energy of each particle does not change, therefore if we use the conservation of energy.
The energy of each photon can be transformed into kinetic energy and as this energy does not change, the energy of both photoelectrons remains constant, only the number of electrons expelled changes.
1. A perspex box has a 10 cm square base and contains water to a height of 10 cm. A piece of rock of mass 600g is lowered into the water and the level rises to 12 cm.
(a) What is the volume of water displaced by the rock?
(b) What is the volume of the rock?
(c) Calculate the density of the rock
Answer:
(a) The volume of water is 100 cm³
(b) The volume of the rock is 20 cm³
(c) The density of the rock is 30 g/cm³
Explanation:
The given parameters of the perspex box are;
The area of the base of the box, A = 10 cm²
The initial level of water in the box, h₁ = 10 cm
The mass of the rock placed in the box, m = 600 g
The final level of water in the box, h₂ = 12 cm
(a) The volume of water in the box, 'V', is given as follows;
V = A × h₁
∴ The volume of water in the box, V = 10 cm² × 10 cm = 100 cm³
The volume of water in the box, V = 100 cm³
(b) When the rock is placed in the box the total volume, [tex]V_T[/tex], is given by the sum of the rock, [tex]V_r[/tex], and the water, V, is given as follows;
[tex]V_T[/tex] = [tex]V_r[/tex] + V
[tex]V_T[/tex] = A × h₂
∴ [tex]V_T[/tex] = 10 cm² × 12 cm = 120 cm³
The total volume, [tex]V_T[/tex] = 120 cm³
The volume of the rock, [tex]V_r[/tex] = [tex]V_T[/tex] - V
∴ [tex]V_r[/tex] = 120 cm³ - 100 cm³ = 20 cm³
The volume of the rock, [tex]V_r[/tex] = 20 cm³
(c) The density of the rock, ρ = (Mass of the rock, m)/(The volume of the rock)
∴ The density of the rock, ρ = 600 g/(20 cm³) = 30 g/cm³
which causes magnets to stick to metal
Answer:
Steel
Explanation:
Steel is a metal that magnets stick to because iron can be found inside steel
Answer:Magnets stick to any metal that contains iron, cobalt or nickel.
Explanation:Iron is found in steel, so steel attracts a magnet and sticks to it. Stainless steel, however, does not attract a magnet.
what is amplitudes relationship between sound and amplitudes
Answer:
A sound wave's amplitude relates to changes in pressure. The sound is perceived as louder if the amplitude increases, and softer if the amplitude decreases. This is illustrated below. DOSITS short video on amplitude.
____ is a chemical messenger released by virus infected cells
Answer:
Cytokines is the answer
Explanation:
it is another word for the chemical messanger
Rhodium is in period 5 of the periodic table. What does this tell you about this element
Answer:
. It is an extraordinarily rare, silvery-white, hard, corrosion-resistant, and chemically inert transition metal. It is a noble metal and a member of the platinum group.
Explanation:
an iron Tyre of diameter 50cm at 288k is to be shrank on to a wheel of diameter 50.35cm.To what temperature must the tyre be heated so that it will slip over the wheel with a radial gap of 0.5mm.Linear expansivity of iron is 0.000012k-1
Answer:
The answer should be D
Explanation:
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