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
butalik [34]
3 years ago
14

When a carpenter shuts off his circular saw, the 10.0 inch diameter blade slows from 4250 rpm to 0.00 in 4.00 s. (a) What is the

angular acceleration of the blade? (b) What is the distance traveled by a point on the rim of the blade during the deceleration? (c) What is the magnitude of the displacement of a point on the rim of the blade during the deceleration?
Physics
1 answer:
MaRussiya [10]3 years ago
4 0

Answer:

(a) \alpha=-111.26rad/s

(b) s=4450.6in

(c) 8.66in

Explanation:

First change the units of the velocity, using these equivalents 1rev=2\pi rad and 1 min =60s

4250rpm(\frac{2\pi rad}{1rev})(\frac{1 min}{60 s} )=445.06rad/s

The angular acceleration \alpha the time rate of change of the angular speed \omega according to:

\alpha=\frac{\Delta \omega}{\Delta t}

\Delta  \omega=\omega_i-\omega_f

Where \omega_i is the original velocity, in the case the velocity before starting the deceleration, and \omega_f is the final velocity, equal to zero because it has stopped.

\alpha=\frac{\Delta \omega}{\Delta t} =\frac{\omega_i-\omega_f}{4}\frac{0-445.06}{4} =\frac{-445.06}{4} =-111.26rad/s

b) To find the distance traveled in radians use the formula:

\theta = \omega_i t + \frac{1}{2} \alpha t^2

\theta = 445.06 (4) + \frac{1}{2}(-111.26) (4)^2=1780.24-890.12=890.12rad

To change this result to inches, solve the angular displacement \theta for the distance traveled s (r is the radius).

\theta=\frac{s}{r} \\s=\theta r

s=890.12(5)=4450.6in

c) The displacement is the difference between the original position and the final. But in every complete rotation of the rim, the point returns to its original position. so is needed to know how many rotations did the point in the 890.16 rad of distant traveled:

\frac{890.12}{2\pi}=141.6667

The real difference is in the 0.6667 (or 2/3) of the rotation. To find the distance  between these positions imagine a triangle formed with the center of the blade (point C), the initial position (point A) and the final position (point B). The angle \gamma=\frac{2\pi}{3}=\frac{360^o}{3}=120 is between the two sides known. Using the theorem of the cosine we can find the missing side of the the triangle(which  is also the net displacement):

c^2=a^2+b^2-2abcos(\gamma)

c^2=5^2+5^2-2(5)(5)cos(\frac{2\pi}{3} )\\c^2=25+25+25\\c^2=75\\c=5\sqrt{3}=8.66in

You might be interested in
How can we avoid injuries in school or community when engaging in physical activities?
Mazyrski [523]

Answer:

  • we should not fight with each other
3 0
3 years ago
If a farsighted person has a near point that is 0.600 mm from the eye, what is the focal length f2f2f_2 of the contact lenses th
Readme [11.4K]

Answer:

0.22mm

Explanation:

A far sighted person is a person suffering from long sightedness i.e such individual can only see far distant object clearly but not near distant object. The defect is corrected using convex lens.

Since convex lens is used, the focal (f) length of the lens is positive and the image distance (v) is also positive.

Using the lens formula,

1/f = 1/u + 1/v

Where u is the object distance = 0.35mm

v = 0.6mm

1/f = 1/0.35+1/0.6

1/f = 2.86 + 1.67

1/f = 4.53

f = 1/4.53

f = 0.22mm

The focal length of the contact lenses will be 0.22mm

5 0
3 years ago
20 POINTS
bekas [8.4K]
They can pretty much be by water i think
5 0
3 years ago
A light bulb will glow when electrons flow through it. As the electron flow increases, the brightness increases as well. A stude
Inga [223]
The correct answer is: <span>Unscrew one light, if the others remain on it is a parallel circuit.</span>
6 0
3 years ago
Read 2 more answers
What determines if a material is a conductor or an insulator? Explain your answer and provide at least one example of each.
Dmitry [639]
A conducting material conducts or allows electricity to flow, while an insulator does not allow electricity to flow. For example think of a water pipe, if the pipe has a hole water can flow, on the other hand if it is just a solid rod, no water can flow through. I hope this helps.
4 0
3 years ago
Other questions:
  • A person is able to pull a rope with a force of 700 N. What is the minimum number of fixed and moveable pulleys that the person
    15·2 answers
  • A sound from a source has an intensity of 270 db when it is 1 m from the source. what is the intensity of the sound when it is 3
    8·1 answer
  • A 1000-kg space probe is motionless in space. to start moving, its main engine is fired for 5 s during which time it ejects exha
    12·1 answer
  • With that push, they have accelerated their masses, which means they have _____ of their bodies.
    8·2 answers
  • Who created a steel plow
    12·2 answers
  • At the interface of two transparent media, light ray experiences both refraction and reflection. Does the angle of reflection de
    13·1 answer
  • You are working for a craft store in the manufacturing department. The craft store does an excellent business selling frames for
    7·1 answer
  • A 1.5m wire carries a 6 A current when a potential difference of 61 V is applied. What is the resistance of the wire?
    8·1 answer
  • How do volcanos effect ecosystems? in ur own words please!!
    7·1 answer
  • PLEASE HELP! Describe how you could use a negatively charged Van de Graaff generator to induce a positive charge on a previously
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!