A 20 ft ladder leans against a wall. The bottom of the ladder is 3 ft from the wall at time t=0 and slides away from the wall at a rate of 2ft/sec. Find the velocity of the top of the ladder at time t=1.

Answers

Answer 1

Answer: 0.516 ft/s

Explanation:

Given

Length of ladder L=20 ft

The speed at which the ladder moving away is v=2 ft/s

after 1 sec, the ladder is 5 ft away from the wall

So, the other end of the ladder is at

[tex]\Rightarrow y=\sqrt{20^2-5^2}=19.36\ ft[/tex]

Also, at any instant t

[tex]\Rightarrow l^2=x^2+y^2[/tex]

differentiate w.r.t.

[tex]\Rightarrow 0=2xv+2yv_y\\\\\Rightarrow v_y=-\dfrac{x}{y}\times v\\\\\Rightarrow v_y=-\dfrac{5}{19.36}\times 2=0.516\ ft/s[/tex]

A 20 Ft Ladder Leans Against A Wall. The Bottom Of The Ladder Is 3 Ft From The Wall At Time T=0 And Slides

Related Questions

Which of the following happens to
density as air pressure decreases?
С C
A. Density increases.
B. Density stays the same.
C. Density decreases.
D. There is no correlation between air pressure and
density.

Answers

Explanation:

As pressure increases, with temperature constant, density increases. Conversely when temperature increases, with pressure constant, density decreases. Air density will decrease by about 1% for a decrease of 10 hPa in pressure or 3 °C increase in temperature.

How does the force of gravity and the force of earth contribute to africa's poverty?

Answers

Answer:

The force of gravity is not the same as being on the earth. when your on the earth there no gravitational pull its all up to the air

Explanation:

No explanation

A solenoid that is 93.9 cm long has a cross-sectional area of 17.3 cm2. There are 1270 turns of wire carrying a current of 7.80 A. (a) Calculate the energy density of the magnetic field inside the solenoid. (b) Find the total energy in joules stored in the magnetic field there (neglect end effects).

Answers

Answer:

[tex]65.6\ \text{J/m}^3[/tex]

[tex]0.11\ \text{J}[/tex]

Explanation:

B = Magnetic field = [tex]\mu_0 \dfrac{N}{l}I[/tex]

[tex]\mu_0[/tex] = Vacuum permeability = [tex]4\pi10^{-7}\ \text{H/m}[/tex]

N = Number of turns = 1270

[tex]l[/tex] = Length of solenoid = 93.9 cm = 0.939 m

[tex]I[/tex] = Current = 7.8 A

A = Area of solenoid = [tex]17.3\ \text{cm}^2[/tex]

Energy density of a solenoid is given by

[tex]u_m=\dfrac{B^2}{2\mu_0}\\\Rightarrow u_m=\dfrac{(\mu_0 \dfrac{N}{l}I)^2}{2\mu_0}\\\Rightarrow u_m=\dfrac{\mu_0N^2I^2}{2l^2}\\\Rightarrow u_m=\dfrac{4\pi\times 10^{-7}\times 1230^2\times 7.8^2}{2\times 0.939^2}\\\Rightarrow u_m=65.6\ \text{J/m}^3[/tex]

The energy density of the magnetic field inside the solenoid is [tex]65.6\ \text{J/m}^3[/tex]

Energy is given by

[tex]U_m=u_mAl\\\Rightarrow U_m=65.6\times 17.3\times 10^{-4}\times 0.939\\\Rightarrow U_m=0.11\ \text{J}[/tex]

The total energy in joules stored in the magnetic field is [tex]0.11\ \text{J}[/tex].

When a 20 kg explosive detonates and sends a 5 kilogram piece traveling to the right at 105 m/s
what is the speed and direction of the other 15 kilogram piece of the explosive!

Answers

Answer:

speed: 35m/s

direction: left

Explanation:

Assuming the right side is the positive direction:

before explosion:

P = mv = 0

after explosion:

P' = 15P + 5P

(Set the velocity of the 15kg piece after explosion as v1' and the velocity of the 5kg piece after explosion as v2')

P' = 0.75mv1' + 0.25mv2'

P' = (15kg)v' + (5kg)(105m/s)

P' = 525kg/m/s + (15kg)v1'

P = P'

525kg/m/s + (15kg)v1' = 0

(15kg)v1' = -525kg/m/s

v1' = -35m/s

speed = |-35| = 35m/s

direction is to the left since the right side is the positive direction.

Will give brainliest!

Describe how heat is moving in the image and label each as Radiation, Conduction, or Convection.

Radiation / Conduction / Convection ​

Answers

Answer:

well in the pot there is conventional heat, the pot itself is giving off conductable heat, and the radiational heat is coming from the stove.

How many gallons of water does it take to produce the following:
a. Cheeseburger
b. Pound of butter
c. A pair of jeans

Answers

Answer:

a. 660 gallons

b.665 gallons

c. 1,800

One end of a meter stick is pinned to a table, so the stick can rotate freely in a plane parallel to the tabletop. Two forces, both parallel to the tabletop, are applied to the stick in such a way that the net torque is zero. The first force has a magnitude of 2.00 N and is applied perpendicular to the length of the stick at the free end. The second force has a magnitude of 6.00 N and acts at a 42.9o angle with respect to the length of the stick. Where along the stick is the 6.00-N force applied? Express this distance with respect to the end of the stick that is pinned.

Answers

Answer:

  x = 0.455 L

Explanation:

For this exercise we must use the rotational equilibrium condition

        Σ τ = 0

it has two forces, the first is perpendicular to the rod, so its stub is

         τ₁ = F₁ L

the second force is applied with an angle, so we can use trigonometry to find its components

          sin θ = F_parallel / F₂

          cos θ = F_perpendicular / F₂

         F_parallel = F₂ sin θ

         F _perpendicular = F₂ cos θ

torque is

         τ₂ = F_perpendicular x + F_parallel 0

the parallel force is on the rod therefore its distance is zero

           

we apply the equilibrium equation

          τ₁  - τ₂ = 0

          F₁ L = F₂ cos θ  x

          x = [tex]\frac{L}{cos \theta} \ \frac{F_1}{F_2}[/tex]

let's calculate

          x = [tex]\frac{L}{cos \ 42.9} \ \frac{2.00}{6.00}[/tex]

          x = 0.455 L

Can someone tell me anything useful about energy management in the human body?

Answers

Answer:

The human body carries out its main functions by consuming food and turning it into usable energy. Immediate energy is supplied to the body in the form of adenosine triphosphate (ATP). Since ATP is the primary source of energy for every body function, other stored

Explanation:

this what teacher explain to us

2. Plastic is a great conductor of charge so it moves quicker.

True
False

Answers

Answer:

the answer is false

Explanation:

plastic doesnt conduct anything

What is the order of the events for the water cycle on a typical warm day?
А
rain, snow, sleet
B
precipitation, evaporation, rain
с
evaporation, condensation, precipitation
D
condensation, evaporation, precipitation

Answers

B precipitation,condensation,precipitation

would it be m/s or kg?

Answers

Answer:

m.s

Explanation:

The elastic energy stored in your tendons can contribute up to 35 % of your energy needs when running. Sports scientists have studied the change in length of the knee extensor tendon in sprinters and nonathletes. They find (on average) that the sprinters' tendons stretch 41 mm , while nonathletes' stretch only 33 mm .

Answers

Hello. Your question is incomplete. However, I managed to find it completely on the internet and I realized that you forgot to mention that the question asks you for the maximum energy difference between velovistas and non-athletes, considering that the spring constant for the tendon of the two groups is equal to 33n/mm.

To make this calculation you will need to use Hooke's law, using the formula: ¹/2*K*x², where "K" will be the value of the spring constant for the tendon and "X" will be the value of the sprinter and non-athlete terms.

So for the sprinter we will have the calculation:

¹/2*33*41² -------> 0,5*33*1681 = 27736. 5 Nmm

(To facilitate the calculation, first solve the division of ¹/2 and then multiply 41 by 41, lastly, just multiply all the results.)

For the non-athlete we will have the calculation:

¹/2*33*33² -------> 0,5*33*1089 = 17968. 5 Nmm

(To facilitate the calculation, first solve the division of ¹/2 and then multiply 41 by 41, lastly, just multiply all the results.)

Now, to reach the final result, you only need to subtract the two values presented by the sprinter and the non-athlete.

27736.5 - 17968.5 = 9768 Nmm

Convert (a) 50 oF, (b) 80 oF, (c) 95 oF to Celsius

Answers

I really need these points thx a lot

Calculate the terminal velocity of
the following nain drops faning
through air (a) one with a diameter
of 0.3cm 6 one with a a diameter
of o. Olm. Take the density of
water to be looo Kym3 and the
eis cosity of air to be ixlos pas.
The buoyancy effect of the air
may be ignored)​

Answers

I’m pretty sure it’s a

What voltage would be measured across the 15 ohm resistor?
A)
2.5 volts
B)
5.0 volts
C)
7.5 volts
D)
10 volts

Answers

Answer:

7.5 volts

Explanation:

I did it on USA Testprep

A baby carriage is sitting at the top of a hill that is 21 m high. The carriage with the baby weighs 20
kg. The carriage has
energy. Calculate it

Answers

Answer:

Energy in carriage (Potential energy) = 4,116 J

Explanation:

Given:

Mass of baby = 20 kg

Height = 21 m

Find:

Energy in carriage (Potential energy)

Computation:

The energy accumulated in an object as a result of its location relative to a neutral level is known as potential energy.

In carriage accumulated energy is potential energy.

Energy in carriage (Potential energy) = mgh

Energy in carriage (Potential energy) = (20)(9.8)(21)

Energy in carriage (Potential energy) = 4,116 J

Why is it harder to breathe on a
mountain?
A. The air pressure is so high the lungs can't expand.
B. The air is denser and oxygen can't flow easily into the
lungs.
C. The denser oxygen molecules sink below the
surrounding air.
D. The air is less dense so there are fewer oxygen
molecules.

Answers

I think it’s d but I’m not sure

A scientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). She aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). The index of refraction of water is 1.33.
Part A: The index of refraction of the oil is 1.20. What is the minimum thickness of the oil slick at that spot? t= 313nm
Part B: Suppose the oil had an index of refraction of 1.50. What would the minimum thickness be now? t=125nm

Answers

Answer:

a) The minimum thickness of the oil slick at the spot is 313 nm

b) the minimum thickness be now will be 125 nm

Explanation:  

Given the data in the question;

a) The index of refraction of the oil is 1.20. What is the minimum thickness of the oil slick at that spot?

t[tex]_{min[/tex] = λ/2n

given that; wavelength λ = 750 nm and  index of refraction of the oil n = 1.20

we substitute

t[tex]_{min[/tex] = 750 / 2(1.20)

t[tex]_{min[/tex] = 750 / 2.4

t[tex]_{min[/tex] = 312.5 ≈ 313 nm

Therefore, The minimum thickness of the oil slick at the spot is 313 nm

b)

Suppose the oil had an index of refraction of 1.50. What would the minimum thickness be now?

minimum thickness of the oil slick at the spot will be;

t[tex]_{min[/tex] = λ/4n

given that; wavelength λ = 750 nm and  index of refraction of the oil n = 1.50

we substitute

t[tex]_{min[/tex] = 750 / 4(1.50)

t[tex]_{min[/tex] = 750 / 6

t[tex]_{min[/tex] = 125 nm

Therefore, the minimum thickness be now will be 125 nm

the higher the objects " ? ", the more kinetic energy

Answers

ANSWER: friction


STEP BY STEP EXPLANATION:

The following statements address the science behind the pulley system illustrated:
A. The pulleys increase the entropy of the system.
B. The force applied to the rope is less than the force needed to lift the object.
C. The pulleys help generate as much energy as possible.
D. The pulleys multiply energy input, resulting in more energy output.
E. The pulleys generate no thermal energy.
Which of these statements is/are true?
i. Statements A and B
ii. Statements D and E
iii. Only statement C
iv. All of the statements

Answers

Answer:

i. Statements A and B

Explanation:

Sana nakatulong

A 1.65-m-long wire having a mass of 0.100 kg is fixed at both ends. The tension in the wire is maintained at 16.0 N. (a) What are the frequencies of the first three allowed modes of vibration

Answers

Answer:

Explanation:

mass per unit length ρ = .100 / 1.65 = .0606 . kg /m

length of wire L = 1.65 m

For fundamental frequency , the expression is as follows

n = [tex]\frac{1}{2L} \sqrt{\frac{T}{m} }[/tex]

L = 1.65 , T = 16 n and m = .0606

n = [tex]\frac{1}{2\times 1.65} \sqrt{\frac{16}{.0606} }[/tex]

= 4.9 /s .

This is fundamental frequency .

other mode of vibration ( first three ) will be as follows

4.9 x 2 = 9.8 /s ,

4.9 x 3 = 14.7 /s .

Which device converts electric energy into mechanical energy?
O A. An electromagnet
O B. A motor
O C. A transformer
O D. A generator

Answers

Answer:

B motor

Explanation:

b. Calculate the kinetic energy of the car for group A.

Answers

Answer: Kinectic Energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity.

Explanation: If an object with a mass of 10 kg (m=10 kg) is moving at a velocity of 5 meters per second (v=5 m/s), the kinetic energy is equal to 125 Joules, or (1/2* 10 kg) * 5 m/s^2.

What is the importance of using locally available resources in creating art?​

Answers

Answer:

please give me brainlist and follow

Explanation:

Using locally available resources for art help in the preservation of environment. A significant and practical aspects of art is material significance. The items used by artists while making an art piece affects both the form and the material. Every material delivers something special in the creative process.

a disk of a radius 50 cm rotates at a constant rate of 100 rpm. what distance in meters will a point on the outside rim travel during 30 seconds of rotation?​

Answers

Each minute, the disk completes 100 revolutions, so a point on the rim traverses a distance of 100 times the circumference of the disk and would have a linear speed of

100 rev/min

= (100 rev/min) × (2π × 50 cm/rev) × (1/100 m/cm) × (1/60 min/s)

= 5π/3 m/s ≈ 5.236 m/s

Then after 30 s of rotation, the point would have traveled a distance of

(5π/3 m/s) × (30 s) = 50π m ≈ 157.08 m

why is potassium and sodium considered as reactive metals?​

Answers

Answer:

because they are found freely in nature uncombined so they are highly reactive with other elements

As potassium is larger than sodium, potassium's valence electron is at a greater distance from the attractive nucleus and is so removed more easily than sodium's valence electron. As it is removed more easily, it requires less energy, and can be said to be more reactive.
Hopefully this helps you! Have a great day!
❤️

true or false

The Total electric potential due to two or more charges is equal to the algebraic sum of the potentials due to the individual charges.

Answers

Answer:

i guess the answer is false

Which of the
following
DECREASES
as you go UP a
mountain?
A. climate
B. altitude
C. amount of oxygen
D. buoyancy

Answers

C. Amount of oxygen

The others either change but don’t decrease or they increase.

Answer:

C. Amount of oxygen

Explanation:

Options A and D are invalid as they aren't affecting factors.

Option B is false as the altitude increases as you go up a mountain.

Option C is true as the air pressure (atmospheric pressure) is inversely proportional to the height/altitude of the mountain.

The liquid emerges into a vertical jet as it drains from the container, with the velocity profile in the jet remaining uniform. The outlet of the container is located 2.0 m above ground, and the radius of the emerging liquid jet changes with vertical distance from the bottom of the container as it accelerates under the action of gravity. Neglecting viscous losses and surface tension effects in the liquid jet, what is the velocity of the water jet as it strikes the ground when the container begins to drain

Answers

Answer:

6.26 m/s

Explanation:

Since we are neglecting viscous losses and surface tension effects in the liquid jet, by conservation of energy, the potential energy loss of the jet = kinetic energy gain of the jet

So, mgh = 1/2mv² where m = mass of water in jet, g = acceleration due to gravity = 9.8 m/s², h = height of outlet = 2.0 mand v = velocity of liquid jet

So, mgh = 1/2mv²

gh = 1/2v²

v² = 2gh

v = √(2gh)

v = √(2 × 9.8 m/s² × 2.0 m)

v = √(39.2 m²/s²)

v = 6.26 m/s

A +0.0129 C charge feels a 4110 N
force from a -0.00707 C charge. How
far apart are they?
[?] m

Answers

Answer:

r = 14.13 m

Explanation:

Given that,

Charge 1, q₁ = +0.0129 C

Charge 2, q₂ = -0.00707 C

The force between charges, F = 4110 N

We need to find the distance between charges. The formula for the force between charges is given by :

[tex]F=k\dfrac{q_1q_2}{r^2}[/tex]

Where

r is the distance between charges

So,

[tex]r=\sqrt{\dfrac{kq_1q_2}{F}} \\\\r=\sqrt{\dfrac{9\times 10^9\times 0.0129 \times 0.00707 }{4110 }} \\\\r=14.13\ m[/tex]

So, the distance between charges is equal to 14.13 m.

Answer:

14.13 m

Explanation:

acellus

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