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Ch 10: Dynamics of Rotational Motion
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610당신이 사용하는 게 아니라요?교과서 변경
10장, 문제 10.4

Three forces are applied to a wheel of radius 0.350 m, as shown in Fig. E10.4. One force is perpendicular to the rim, one is tangent to it, and the other one makes a 40.0° angle with the radius. What is the net torque on the wheel due to these three forces for an axis perpendicular to the wheel and passing through its center?

검증된 단계별 안내
1
Identify the forces acting on the wheel: 11.9 N perpendicular to the rim, 8.50 N tangent to the rim, and 14.6 N at a 40.0° angle to the radius.
Recall the formula for torque: \( \tau = r \cdot F \cdot \sin(\theta) \), where \( r \) is the radius, \( F \) is the force, and \( \theta \) is the angle between the force and the lever arm.
Calculate the torque for the 11.9 N force: Since it is perpendicular to the radius, \( \theta = 90° \), so \( \tau_1 = 0.350 \text{ m} \cdot 11.9 \text{ N} \cdot \sin(90°) \).
Calculate the torque for the 8.50 N force: It is tangent to the rim, so \( \theta = 90° \), thus \( \tau_2 = 0.350 \text{ m} \cdot 8.50 \text{ N} \cdot \sin(90°) \).
Calculate the torque for the 14.6 N force: It makes a 40.0° angle with the radius, so \( \tau_3 = 0.350 \text{ m} \cdot 14.6 \text{ N} \cdot \sin(40.0°) \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
6m
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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Torque

Torque is a measure of the rotational force applied to an object, calculated as the product of the force and the lever arm distance from the axis of rotation. It is given by the formula τ = r × F × sin(θ), where r is the radius, F is the force, and θ is the angle between the force and the lever arm. Torque determines how effectively a force can rotate an object around an axis.
추천 영상:
가이드 코스
08:55
Net Torque & Sign of Torque

Lever Arm

The lever arm is the perpendicular distance from the axis of rotation to the line of action of the force. It is crucial in calculating torque because it determines the effectiveness of the force in causing rotational motion. A longer lever arm increases the torque for the same amount of force, making it easier to rotate the object.
추천 영상:
가이드 코스
06:58
Ice skater closes her arms

Net Torque

Net torque is the sum of all individual torques acting on an object, taking into account their directions. It determines the overall rotational effect on the object. If the net torque is zero, the object remains in rotational equilibrium, meaning it does not start rotating or change its rotational speed. Calculating net torque involves adding torques that cause rotation in the same direction and subtracting those that oppose it.
추천 영상:
가이드 코스
08:55
Net Torque & Sign of Torque
관련 실천
교과서 질문

A cord is wrapped around the rim of a solid uniform wheel 0.250 m in radius and of mass 9.20 kg. A steady horizontal pull of 40.0 N to the right is exerted on the cord, pulling it off tangentially from the wheel. The wheel is mounted on frictionless bearings on a horizontal axle through its center. Find the magnitude and direction of the force that the axle exerts on the wheel.

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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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A machine part has the shape of a solid uniform sphere of mass 225 g and diameter 3.00 cm. It is spinning about a frictionless axle through its center, but at one point on its equator, it is scraping against metal, resulting in a friction force of 0.0200 N at that point. Find its angular acceleration.

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