1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Viktor [21]
3 years ago
9

A girl flies a kite at a height of 500 ft, the wind carrying the kite horizontally away from her at a rate of 20 ft/sec. How fas

t must she let out the string when the kite is 700 ft away from her? ft/sec
Physics
1 answer:
olya-2409 [2.1K]3 years ago
3 0

Answer:

she must let out the string when the kite is 700 ft away from her at 20 ft/s

Explanation:

given information:

a = the distance between the girl

b = the length of the string

a = 300

da/dt = 20 ft/s

c =500 ft, dc/dt = ?

Pythagorean Theorem,

a^{2} + 300^{2}= c^{2}

when y = 500

a^{2} + 300^{2}= 500^{2}

a = \sqrt{500^{2} - 300^{2}}

  = 400

thus

a^{2} + 300^{2}= c^{2}

2a da/dt = 2c dc/dt

a da/dt = c dc/dt

400 (25) = 500 dc/dt

dc/dt = 1000/500

         = 20 ft/s

You might be interested in
Convert 1erg into joule by dimensional method​
Valentin [98]

Answer:

1 * 10^-7 [J]

Explanation:

To solve this problem we must use dimensional analysis.

1 ergos [erg] is equal to 1 * 10^-7 Joules [J]

1[erg]*\frac{1*10^{-7} }{1}*[\frac{J}{erg} ] \\= 1*10^{-7}[J]

4 0
2 years ago
A certain superconducting magnet in the form of a solenoid of length 0.72 m can generate a magnetic field of 3.5 T in its core w
ira [324]

Answer:

55407

Explanation:

we have given that magnetic field B=3.5 T

current through the coil=90 A

Length of solenoid =0.72 m

we know the formula of magnetic field

B=\frac{\mu _0NI}{l}

so N=\frac{Bl}{\mu _0I}=\frac{3.5\times 0.72}{4\pi \times 10^{-6}\times 90}=55407.277=55407\ turns

so the number of turn in solenoid will be 55407

3 0
2 years ago
calculate the kinetic energy of a car with a mass of 500kg traveling at a velocity of 10m/s^2 north. A) 2,500j B) 25,000j C) 50,
Arte-miy333 [17]
The correct answer would be A) 2,500j
8 0
2 years ago
It is possible to convert radiant energy into electrical energy using photovoltaic cells. Assuming equal efficiency of conversio
Finger [1]

Answer:

Ultraviolet radiation would yield more electrical energy

Explanation:

The reason for the ultraviolet to generate more energy is that there would be getting more electrons per unit of time the photovoltaic cell, due to the higher frequency of the ultraviolet in comparison with the infrared radiation.

The infrared spectrum goes from 300 GHz (10^9 Hertz) to 400 THz or (10^12 Hertz).

The ultraviolet spectrum goes from 800 THz to 30.000 THz or (10^12 Hertz). This kind of radiation is responsible for skin burn from the sun and it´s the “ most usable” part from the sunlight in a photovoltaic cell.

4 0
2 years ago
How far does light travel in the time it takes sound to travel 1 cm in air at 20°c?
kykrilka [37]
The speed of sound at 20^{\circ}C is approximately v=343 m/s. The distance covered by the sound wave is
s=1 cm=0.01 m
And the time it takes is
t= \frac{S}{v}= \frac{0.01 m}{343 m/s}=2.9 \cdot 10^{-5} s

Now we want to find how far the light travels during this time. Light travels at speed c=3 \cdot 10^8 m/s, therefore the distance it covers during this time is
S=ct = (3 \cdot 10^8 m/s)(2.9 \cdot 10^{-5} s)=8700 m
8 0
2 years ago
Other questions:
  • The rate an object is moving relative to a reference point is its
    5·1 answer
  • If a car skids 66 ft on wet concrete, how fast was it moving when the brakes were applied? (Round your answer to the nearest who
    10·1 answer
  • Which form or radiation has the greater frequency?<br> UV radiation or violet light?
    10·2 answers
  • Select the correct answer. What is tan for the given triangle? 0.60 1.67 1.33 5.00 0.20
    11·2 answers
  • 1.A little girl kicks a soccer ball. It goes 10 feet and comes back to her. How is this possible?
    14·2 answers
  • Write down an equation describing a sinusoidal traveling wave (in 1-D). Tell us (words and/or equations) what in your equation t
    10·1 answer
  • Which state Which states of matter have a set volume? Explain why this is, based on the animations you observed for the differen
    9·1 answer
  • It took 1500 Newton's of force to push a car 3 meters. How much work was done
    13·1 answer
  • An experiment is performed on an unknown material and produces the given heat curve. The temperature of the material is shown as
    7·1 answer
  • What are the 3 basic parts of an atom and what are their charges?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!