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Ch 07: Newton's Third Law
Knight Calc - Physics for Scientists and Engineers 5th Edition
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Knight Calc 5th EditionCh 07: Newton's Third Law문제 47
7장, 문제 47

FIGURE P7.47 shows a 200 g hamster sitting on an 800 g wedge-shaped block. The block, in turn, rests on a spring scale. An extra-fine lubricating oil having μs = μk = 0 is sprayed on the top surface of the block, causing the hamster to slide down. Friction between the block and the scale is large enough that the block does not slip on the scale. What does the scale read, in grams, as the hamster slides down?

검증된 단계별 안내
1
Understand the problem: The hamster slides down a frictionless wedge-shaped block, which rests on a spring scale. The goal is to determine the reading of the scale in grams as the hamster slides down. Note that the block does not slip on the scale, and the lubricating oil ensures no friction between the hamster and the block.
Analyze the forces: The spring scale measures the total normal force exerted by the block and the hamster on it. This force is equal to the combined gravitational forces of the block and the hamster, as there is no vertical acceleration of the system.
Express the gravitational forces: The gravitational force acting on the hamster is given by \( F_{\text{hamster}} = m_{\text{hamster}} g \), where \( m_{\text{hamster}} = 0.2 \, \text{kg} \) and \( g = 9.8 \, \text{m/s}^2 \). Similarly, the gravitational force acting on the block is \( F_{\text{block}} = m_{\text{block}} g \), where \( m_{\text{block}} = 0.8 \, \text{kg} \).
Combine the forces: Since the block does not slip on the scale and the hamster's motion is along the inclined surface, the vertical forces add directly. The total force measured by the scale is \( F_{\text{total}} = F_{\text{hamster}} + F_{\text{block}} = (m_{\text{hamster}} + m_{\text{block}}) g \).
Convert to grams: The scale reading is typically given in grams. To convert the total force to grams, use the relationship \( 1 \; \text{kg} = 1000 \; \text{g} \). Thus, the scale reading is \( (m_{\text{hamster}} + m_{\text{block}}) \times 1000 \; \text{g} \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
10m
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주요 개념

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

Friction

Friction is the force that opposes the relative motion of two surfaces in contact. In this scenario, the hamster is sliding down the wedge-shaped block due to the absence of friction (μₛ = μₖ = 0) between them. Understanding friction is crucial as it determines whether an object will remain stationary or move when a force is applied.
추천 영상:
가이드 코스
08:11
Static Friction & Equilibrium

Newton's Second Law

Newton's Second Law states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (F = ma). This principle is essential for analyzing the forces acting on the hamster and the wedge, allowing us to calculate the resultant forces and the reading on the spring scale as the hamster slides down.
추천 영상:
가이드 코스
06:54
Intro to Forces & Newton's Second Law

Weight and Normal Force

Weight is the force exerted by gravity on an object, calculated as the product of mass and gravitational acceleration (W = mg). The normal force is the support force exerted by a surface perpendicular to the object. In this problem, the weight of the hamster and the wedge affects the reading on the scale, as the normal force changes when the hamster slides down the block.
추천 영상:
가이드 코스
08:17
The Normal Force
관련 실천
교과서 질문

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교과서 질문

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