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
FrozenT [24]
3 years ago
9

A top is a toy that is made to spin on its pointed end by pulling on a string wrapped around the body of the top. The string has

a length of 51 cm and is wrapped around the top at a place where its radius is 1.8 cm. The thickness of the string is negligible. The top is initially at rest. Someone pulls the free end of the string, thereby unwinding it and giving the top an angular acceleration of 10 rad/s2. What is the final angular velocity of the top when the string is completely unwound
Physics
1 answer:
AlladinOne [14]3 years ago
3 0

Given Information:

Angular displacement = θ = 51 cm = 0.51  m

Radius = 1.8 cm = 0.018 m

Initial angular velocity = ω₁ = 0 m/s

Angular acceleration = α = 10 rad/s ²

Required Information:

Final angular velocity = ω₂ = ?

Answer:

Final angular velocity = ω₂ = 21.6 rad/s

Explanation:

We know from the equations of kinematics,

ω₂² = ω₁² + 2αθ

Where ω₁ is the initial angular velocity that is zero since the toy was initially at rest, α is angular acceleration and θ is angular displacement.

ω₂² = (0)² + 2αθ

ω₂² = 2αθ

ω₂ = √(2αθ)

We know that the relation between angular displacement and arc length is given by

s = rθ

θ = s/r

θ = 0.51/0.018

θ = 23.33 radians

finally, final angular velocity is

ω₂ = √(2αθ)

ω₂ = √(2*10*23.33)

ω₂ = 21.6 rad/s

Therefore, the top will be rotating at 21.6 rad/s when the string is completely unwound.

You might be interested in
A nucleus with a mass number of 64 has a mean radius of about: _________.
dangina [55]

Answer:

The correct option is A

Explanation:

From the question we are told that

The mass number is A= 64

Generally the mean radius is mathematically evaluated as

R  =  R_o A^{\frac{1}{3} }

Here R_o is a constant with a value  R_o =1.2*10^{-15}

So  

     R  =  1.2*10^{-15} *  64^{\frac{1}{3} }

      R  =   4.8 *10^{-15}

        R  =   4.8\ fm

5 0
2 years ago
Precautions to be taken for the displacement method
finlep [7]

Volume by Displacement. The displacement method (submersion, or dunking method) can be used to accurately measure the volume of the human body and other oddly shaped objects by measuring the volume of fluid displaced when the object is submerged.

The following precautions should be taken very observantly:-

The line of sight must be perpendicular to measuring scale to avoid parallax error. Formation of bubbles inside the cylinder should be completely avoided. Any bubbles within leads to wrong measurements.

8 0
3 years ago
The kinetic energy of a body of mass 15 kg is 30 joule. What is its momentum?
lys-0071 [83]

This problem is a piece o' cake, IF you know the formulas for both kinetic energy and momentum.  So here they are:

Kinetic energy = (1/2) · (mass) · (speed²)

Momentum = (mass) · (speed)

So, now ... We know that

==> mass = 15 kg,  and

==> kinetic energy = 30 Joules

Take those pieces of info and pluggum into the formula for kinetic energy:

Kinetic energy = (1/2) · (mass) · (speed²)

30 Joules = (1/2) · (15 kg) · (speed²)

60 Joules = (15 kg) · (speed²)

4 m²/s² = speed²

Speed = 2 m/s

THAT's all you need !  Now you can find momentum:

Momentum = (mass) · (speed)

Momentum = (15 kg) · (2 m/s)

<em>Momentum = 30 kg·m/s</em>

<em>(Notice that in this problem, although their units are different, the magnitude of the KE is equal to the magnitude of the momentum.  When I saw this, I wondered whether that's always true.  So I did a little more work, and I found out that it isn't ... it's a coincidence that's true for this problem and some others, but it's usually not true.)</em>

8 0
2 years ago
1) What are the parts of a longitudinal wave? How are they different?<br> ***
Kay [80]

Answer:

Compression- pushing together

Refraction- pulling apart

Wavelength- the length of the wave

Explanation:

I just knew it

~Plz click the crown~

3 0
2 years ago
What is the SI unit of acceleration and work?​
Lerok [7]
A=m/s^2(meter per second square)
Work=joule
6 0
3 years ago
Other questions:
  • A newton-meter is a measure of work also known as the _____.
    11·1 answer
  • A block of mass 0.1 kg is attached to a spring of spring constant 22 N/m on a frictionless track. The block moves in simple harm
    9·1 answer
  • Which is an example of projectile motion?
    5·2 answers
  • Which of the device has the highest resistance?
    11·2 answers
  • A sling-thrower puts a stone (0.250 kg) in the sling's pouch (0.010 kg) and then begins to make the stone and pouch move in a ve
    12·1 answer
  • The electrostatic attractions in crystalline salts, such as sodium chloride, are formed by __________ between positive and negat
    8·2 answers
  • Definition of Xenophobia​
    8·2 answers
  • Kyle runs 20 m north, 20 m west and then 20 m south, what is Kyles’s total displacement?
    9·1 answer
  • If an object travels 245 km in 5 hours, what was the speed of the object?
    15·1 answer
  • Three point charges are fixed in place in a right triangle, as shown in the figure.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!