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Ch 10: Dynamics of Rotational Motion
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610Non è quello che usi tu?Cambia libro di testo
Capitolo 10, Problema 7a

A machinist is using a wrench to loosen a nut. The wrench is 25.0 cm long, and he exerts a 17.0-N force at the end of the handle at 37° with the handle (Fig. E10.7). What torque does the machinist exert about the center of the nut?

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Understand that torque (τ) is the measure of the force that can cause an object to rotate about an axis. It is calculated using the formula τ = r * F * sin(θ), where r is the distance from the axis of rotation to the point where the force is applied, F is the magnitude of the force, and θ is the angle between the force and the lever arm.
Identify the given values from the problem: the length of the wrench (r) is 25.0 cm, which needs to be converted to meters (0.25 m), the force (F) applied is 17.0 N, and the angle (θ) between the force and the wrench is 37°.
Convert the angle from degrees to radians if necessary, but in this case, you can use the sine function directly with degrees. Calculate sin(37°) using a calculator or trigonometric table.
Substitute the values into the torque formula: τ = 0.25 m * 17.0 N * sin(37°).
Perform the multiplication to find the torque exerted by the machinist about the center of the nut. Remember that the unit of torque is Newton-meter (N·m).

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Torque

Torque is a measure of the rotational force applied to an object, calculated as the product of the force and the perpendicular distance from the pivot point to the line of action of the force. It is expressed in Newton-meters (Nm) and determines how effectively a force can cause an object to rotate.
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Lever Arm

The lever arm is the perpendicular distance from the axis of rotation to the line of action of the force. In this problem, the lever arm is the length of the wrench, which is crucial for calculating torque. A longer lever arm increases the torque for the same amount of force applied.
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Angle of Force Application

The angle at which a force is applied affects the torque produced. Torque is maximized when the force is applied perpendicular to the lever arm. The effective component of the force contributing to torque is calculated using the sine of the angle between the force and the lever arm.
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