/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 98 A clay cylinder of radius 20 cm ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

A clay cylinder of radius 20 cm on a potter's wheel spins at a constant rate of 10 rev/s. The potter applies a force of \(10\) \(\mathrm{N}\) to the clay with his hands where the coefficient of friction is 0.1 between his hands and the clay. What is the power that the potter has to deliver to the wheel to keep it rotating at this constant rate?

Short Answer

Expert verified
The power that the potter has to deliver to the wheel to keep it rotating at a constant rate of 10 rev/s is approximately 12.57 W.

Step by step solution

01

Calculate the frictional force

First, we will find the frictional force acting between the potter's hand and the clay. We know the coefficient of friction is 0.1 and the normal force of 10 N is applied by the potter's hand. The frictional force can be calculated by multiplying the coefficient of friction by the normal force. Frictional force (F_friction) = Coefficient of friction (μ) × Normal force (N) F_friction = 0.1 × 10 N F_friction = 1 N
02

Calculate the torque

We know the frictional force, and we need to calculate the torque acting on the wheel. Torque (τ) can be found by multiplying the frictional force by the radius of the clay cylinder. τ = F_friction × radius τ = 1 N × 0.2 m τ = 0.2 Nm
03

Calculate the angular velocity

We are given that the clay cylinder spins at a constant rate of 10 rev/s. To find the angular velocity, we can convert this to radians/second. Angular velocity (ω) = 10 rev/s × \(\frac{2π}{\text{rev}}\) ω = 20π rad/s
04

Calculate the power

Finally, we have all the information we need to find the power (P) that the potter has to deliver to the wheel. Power can be calculated using the formula: P = τ × ω P = 0.2 Nm × 20π rad/s P ≈ 12.57 W Thus, the power that the potter has to deliver to the wheel to keep it rotating at a constant rate of 10 rev/s is approximately 12.57 W.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Torque
Torque is an essential concept in understanding how objects rotate. In simple terms, it is the measure of the force that can cause an object to rotate about an axis. Imagine trying to open a door; the further away you push from the hinge, the easier it is to turn. This is because torque depends not just on the amount of force applied, but also on where it's applied. In the case of the exercise involving the clay cylinder, torque is calculated using the formula:\[ \tau = F_{friction} \times r \]where \(F_{friction}\) is the frictional force and \(r\) is the radius of the cylinder. The torque in this exercise is vital because it's what balances the opposing forces, keeping the wheel spinning at a constant speed.
Angular Velocity
Angular velocity is a measure of how quickly an object rotates or revolves relative to another point, expressed in radians per second. It shows how fast the object moves through an angle in a given time period.In this exercise, the given rotation speed is 10 revolutions per second (rev/s). To convert this into angular velocity, we use the fact that one full revolution equates to \(2\pi\) radians. So, the formula becomes:\[ \omega = 10 \text{ rev/s} \times \frac{2\pi}{1 \text{ rev}} = 20\pi \text{ rad/s} \]This conversion is crucial for using angular velocity in further calculations, such as computing power or torque.
Coefficient of Friction
The coefficient of friction is a dimensionless value that represents the frictional resistance between two surfaces in contact. It ranges between 0 (no friction) and 1 (high friction), and even beyond 1 in extreme cases.For this problem, the coefficient of friction is given as 0.1. This means that the friction between the potter's hand and the clay is relatively low. The frictional force can be calculated by multiplying the coefficient of friction with the normal force:\[ F_{friction} = \mu \times N \]where \(\mu\) is the coefficient of friction and \(N\) is the normal force. With a normal force of 10 N applied by the potter's hands, the resulting frictional force is 1 N, as shown in the solution.
Power Calculation
Power is the rate at which work is done or energy is transferred in physical systems. In rotational systems like the potter's wheel, power is necessary to overcome the resisting frictional forces and maintain motion.The formula for power in terms of torque and angular velocity is:\[ P = \tau \times \omega \]Where \(\tau\) is torque and \(\omega\) is angular velocity. From the exercise, we already know \(\tau = 0.2 \text{ Nm}\) and \(\omega = 20\pi \text{ rad/s}\). Plugging these values into the formula gives:\[ P = 0.2 \text{ Nm} \times 20\pi \text{ rad/s} \approx 12.57 \text{ W} \]This calculation shows that the potter must supply around 12.57 watts of power to keep the clay cylinder rotating steadily.
Frictional Force
Frictional force is a type of force that opposes the relative motion or tendency of such motion of two surfaces in contact. It's essential in many mechanical systems because it lets us grip, stop, or slow down moving objects.In this exercise, frictional force results from the potter applying a normal force to the rotating clay. With a known coefficient of friction (0.1), we calculate frictional force as:\[ F_{friction} = \mu \times N = 0.1 \times 10 \text{ N} = 1 \text{ N} \]This force resists the cylinder's motion and thus needs to be overcome by the applied torque to maintain constant rotation.
Cylindrical Motion
Cylindrical motion involves an object moving in a circular path, like wheels or gears. Analyzing the cylindrical motion requires understanding rotational dynamics, including angular velocity, torque, and friction, as seen in our exercise. For a clay cylinder on a moving potter's wheel, understanding cylindrical motion involves knowing how these forces interact to maintain rotation. Angular velocity provides the speed, while torque acts through the radius to keep it spinning steadily against frictional forces. In practice, the potter must continuously supply energy to maintain this smooth motion, balancing frictional resistance with deliberate force application, ensuring stable cylindrical motion.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A diver goes into a somersault during a dive by tucking her limbs. If her rotational kinetic energy is \(100 \mathrm{J}\) and her moment of inertia in the tuck is \(9.0 \mathrm{kg} \cdot \mathrm{m}^{2}\), what is her rotational rate during the somersault?

A uniform cylindrical grinding wheel of mass \(50.0 \mathrm{kg}\) and diameter \(1.0 \mathrm{m}\) is turned on by an electric motor. The friction in the bearings is negligible. (a) What torque must be applied to the wheel to bring it from rest to \(120 \mathrm{rev} / \mathrm{min}\) in 20 revolutions? (b) A tool whose coefficient of kinetic friction with the wheel is 0.60 is pressed perpendicularly against the wheel with a force of \(40.0\) \(\mathrm{N}\). What torque must be supplied by the motor to keep the wheel rotating at a constant angular velocity?

A phonograph turntable rotating at 33 1/3 rev/min slows down and stops in 1.0 min. (a) What is the turntable's angular acceleration assuming it is constant? (b) How many revolutions does the turntable make while stopping?

The angular velocity of a flywheel with radius 1.0 \(\mathrm{m}\) varies according to \(\omega(t)=2.0 t .\) Plot \(a_{\mathrm{c}}(t)\) and \(a_{\mathrm{t}}(t)\) from \(t=0\) to \(3.0 \mathrm{s}\) for \(r=1.0 \mathrm{m} .\) Analyze these results to explain when \(a_{\mathrm{c}} \gg a_{\mathrm{t}}\) and when \(a_{\mathrm{c}} \ll a_{\mathrm{t}}\) for a point on the flywheel at a radius of \(1.0 \mathrm{m}\).

A sphere of mass \(1.0 \mathrm{kg}\) and radius \(0.5 \mathrm{m}\) is attached to the end of a massless rod of length \(3.0 \mathrm{m}\). The rod rotates about an axis that is at the opposite end of the sphere (see below). The system rotates horizontally about the axis at a constant 400 rev/min. After rotating at this angular speed in a vacuum, air resistance is introduced and provides a force \(0.15 \mathrm{N}\) on the sphere opposite to the direction of motion. What is the power provided by air resistance to the system \(100.0 \mathrm{s}\) after air resistance is introduced?

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.