Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Question:(I) What is the angular momentum of a 0.270-kg ball revolving on the end of a thin string in a circle of radius 1.35 m at an angular speed of 10.4 rad/s?

Short Answer

Expert verified

The angular momentum of the ball is \(5.1\;{\rm{kg}} \cdot {{\rm{m}}^{\rm{2}}}{\rm{/s}}\).

Step by step solution

01

Given data

The mass of the ball is\(m = 0.270\;{\rm{kg}}\).

The radius of the circle is\(r = 1.35\;{\rm{m}}\).

The angular speed is \(\omega = 10.4\;{\rm{rad/s}}\).

02

Understanding angular momentum

In this problem, use the product of the moment of inertia of the ball and its angular speed to evaluate the angular momentum.

03

Determine the angular momentum of the ball

The relation of angular momentum can be written as:

\(\begin{aligned}{l}L &= I\omega \\L &= \left( {m{r^2}} \right)\omega \end{aligned}\)

Here, Iis the moment of inertia of the ball.

On plugging the values in the above relation, you get:

\(\begin{aligned}{l}L &= \left( {0.270\;{\rm{kg}} \times {{\left( {1.35\;{\rm{m}}} \right)}^2}} \right)\left( {10.4\;{\rm{rad/s}}} \right)\\L &= 5.1\;{\rm{kg}} \cdot {{\rm{m}}^{\rm{2}}}{\rm{/s}}\end{aligned}\)

Thus, \(L = 5.1\;{\rm{kg}} \cdot {{\rm{m}}^{\rm{2}}}{\rm{/s}}\) is the required angular momentum.

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 Vaia!

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 small mass m attached to the end of a string revolves in a circle on a frictionless table top. The other end of the string passes through a hole in the table (Fig. 8–62). Initially, the mass revolves with a speed\({v_1} = 2.4\;{\rm{m/s}}\)in a circle of radius\({r_1} = 0.80\;{\rm{m}}\). The string is then pulled slowly through the hole so that the radius is reduced to\({r_2} = 0.48\;{\rm{m}}\). What is the speed,\({v_2}\), of the mass now?

Suppose a star the size of our Sun, but with mass 8.0 times as great, were rotating at a speed of 1.0 revolution every 9.0 days. If it were to undergo gravitational collapse to a neutron star of radius 12 km, losing\(\frac{3}{4}\)of its mass in the process, what would its rotation speed be? Assume the star is a uniform sphere at all times. Assume also that the thrown off mass carries off either (a) no angular momentum, or (b) its proportional share\(\left( {\frac{3}{4}} \right)\)of the initial angular momentum.

A small 350-gram ball on the end of a thin, light rod is rotated in a horizontal circle of a radius of 1.2 m. Calculate (a) the moment of inertia of the ball about the center of the circle and (b) the torque needed to keep the ball rotating at a constant angular velocity if the air resistance exerts a force of 0.020 N on the ball. Ignore the air resistance on the rod and its moment of inertia.

This book has three symmetry axes through its center, all mutually perpendicular. The book’s moment of inertia would be smallest about which of the three? Explain.

The forearm in Fig. 8–46 accelerates a 3.6-kg ball at \({\bf{7}}{\bf{.0}}\;{\bf{m/}}{{\bf{s}}^{\bf{2}}}\) by means of the triceps muscle, as shown. Calculate (a) the torque needed and (b) the force that must be exerted by the triceps muscle. Ignore the mass of the arm.

FIGURE 8-46

Problems 35 and 36

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.

Sign-up for free