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Ch 12: Rotation of a Rigid Body
Knight Calc - Physics for Scientists and Engineers 5th Edition
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796당신이 사용하는 게 아니라요?교과서 변경
12장, 문제 32

A 5.0 kg cat and a 2.0 kg bowl of tuna fish are at opposite ends of the 4.0-m-long seesaw of FIGURE EX12.32. How far to the left of the pivot must a 4.0 kg cat stand to keep the seesaw balanced?

검증된 단계별 안내
1
Step 1: Understand the concept of torque and equilibrium. Torque is the rotational equivalent of force, and for the seesaw to be balanced, the sum of clockwise torques must equal the sum of counterclockwise torques. The formula for torque is τ = F × d, where F is the force (weight) and d is the distance from the pivot point.
Step 2: Calculate the torque produced by the 5.0 kg cat. The weight of the cat is given by F = m × g, where m is the mass (5.0 kg) and g is the acceleration due to gravity (approximately 9.8 m/s²). The distance from the pivot is 2.0 m (half the length of the seesaw). Use the formula τ = F × d to find the torque.
Step 3: Calculate the torque produced by the 2.0 kg bowl of tuna fish. Similarly, the weight of the bowl is F = m × g, where m is 2.0 kg. The distance from the pivot is also 2.0 m. Use the formula τ = F × d to find the torque.
Step 4: Set up the equation for equilibrium. The torque produced by the 4.0 kg cat standing to the left of the pivot must balance the combined torques of the 5.0 kg cat and the 2.0 kg bowl. Let the distance of the 4.0 kg cat from the pivot be x. The torque produced by the 4.0 kg cat is τ = F × x, where F = m × g and m is 4.0 kg.
Step 5: Solve for x. Combine the torques from the 5.0 kg cat and the 2.0 kg bowl on one side of the equation and set it equal to the torque produced by the 4.0 kg cat. Rearrange the equation to isolate x, and solve for the distance the 4.0 kg cat must stand to the left of the pivot.

비슷한 문제에 대한 검증된 영상 답변:

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

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 around a pivot point. It is calculated as the product of the force applied and the distance from the pivot point to the line of action of the force. In this scenario, the seesaw will balance when the torques produced by the weights of the cats and the bowl of tuna are equal.
추천 영상:
가이드 코스
08:55
Net Torque & Sign of Torque

Equilibrium

Equilibrium in physics refers to a state where all forces and torques acting on an object are balanced, resulting in no net force or rotation. For the seesaw to remain in equilibrium, the clockwise torque must equal the counterclockwise torque. This principle is essential for determining the position of the 4.0 kg cat needed to balance the seesaw.
추천 영상:
가이드 코스
10:13
Torque & Equilibrium

Center of Mass

The center of mass is the point at which the mass of an object is concentrated and around which it balances. In the context of the seesaw, the positions of the cats and the bowl of tuna affect the overall center of mass, influencing how far the 4.0 kg cat must stand from the pivot to achieve balance. Understanding this concept helps in calculating the required distances for equilibrium.
추천 영상:
가이드 코스
06:30
Intro to Center of Mass