Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 10: Q59P (page 291)

An automobile crankshaft transfers energy from the engine to the axle at the rate of 100 hp(=74.6 kW) when rotating at a speed of 1800 rev/min. What torque (in newton-meters) does the crankshaft deliver?

Short Answer

Expert verified

Torque delivered by the crankshaft is396 N.m .

Step by step solution

01

Understanding the given information

  1. Power of an automobile crankshaft is,P=100 hp=74.6 kW=74600 W.
  2. The speed is, f=1800 rev/min.
02

Concept and formula used in the given question

You can find thetorque delivered by the crankshaft using the relation between torque, power, and angular speed.

P=τω

03

Calculation for the torque the crankshaft delivers 

Frequency of the rotation of an automobile is

f=1800revmin×1 min60 s=30 rev/s

Angular speed ofan automobile is

ω=2πf=2(3.142)(30 rev/s)=188.52 rad/s

Power of an automobile crankshaft is

P=τωτ=Pω=74600 W188.52 rad/s=395.71 N.m≃396 N.m

Therefore, the torque delivered by the crankshaft is 396 N.m.

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.

Start your free trial

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

Figure 10−43 shows a uniform disk that can rotate around its center like a merry-go-round. The disk has a radius of 2.00 cm and a mass of  20.0 gramsand is initially at rest. Starting at time t=0, two forces are to be applied tangentially to the rim as indicated, so that at time t=1.25 sthe disk has an angular velocity of250 rad/s counterclockwise. Force F→1has a magnitude of0.100 N . What is magnitudeF→2 ?

The thin uniform rod in Fig. 10-53has length 2.0mand can pivot about a horizontal, frictionless pin through one end. It is released from rest at angleθ=40°above the horizontal. Use the principle of conservation of energy to determine the angular speed of the rod as it passes through the horizontal position.

In Fig.10−45a , an irregularly shaped plastic plate with uniform thickness and density (mass per unit volume) is to be rotated around an axle that is perpendicular to the plate face and through point O. The rotational inertia of the plate about that axle is measured with the following method. A circular disk of mass0.500 kg and radius2.00 cm is glued to the plate, with its center aligned with point O(Fig.10−45b ). A string is wrapped around the edge of the disk the way a string is wrapped around a top. Then the string is pulled for 5.00 s. As a result, the disk and plate are rotated by a constant force of 0.400 Nthat is applied by the string tangentially to the edge of the disk. The resulting angular speed is 114 rad/s. What is the rotational inertia of the plate about the axle?

A uniform spherical shell of mass M=4.5kgand radius R=8.5cmcan r otate about a vertical axis on frictionless bearings (Fig.10-47). A massless cord passes around the equator of the shell, over a pulley of rotational inertia l=3.0×10-3kgm2and radius,r=5.0cmand is attached to a small object of mass .m=0.60kgThere is no friction on the pulley’s axle; the cord does not slip on the pulley. What is the speed of the object when it has fallen 82cmafter being released from rest? Use energy considerations.

A pulsar is a rapidly rotating neutron star that emits a radio beam the way a lighthouse emits a light beam. We receive a radio pulse for each rotation of the star. The period T of rotation is found by measuring the time between pulses. The pulsar in the Crab nebula has a period of rotation of T=0.033 s that is increasing at the rate of 1.26×10−5 s/y .

(a) What is the pulsar’s angular acceleration α?

(b) If αis constant, how many years from now will the pulsar stop rotating?

(c) The pulsar originated in a supernova explosion seen in the year 1054 .Assuming constant a, find the initial T.
See all solutions

Recommended explanations on Physics Textbooks

Electrostatics

Read Explanation

Classical Mechanics

Read Explanation

Linear Momentum

Read Explanation

Physical Quantities And Units

Read Explanation

Work Energy and Power

Read Explanation

Conservation of Energy and Momentum

Read Explanation
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