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Ch 08: Dynamics II: Motion in a Plane
Knight Calc - Physics for Scientists and Engineers 5th Edition
Knight Calc5th EditionPhysics for Scientists and EngineersISBN: 9780137344796당신이 사용하는 게 아니라요?교과서 변경
8장, 문제 1

As a science fair project, you want to launch an 800 g model rocket straight up and hit a horizontally moving target as it passes 30 m above the launch point. The rocket engine provides a constant thrust of 15.0 N. The target is approaching at a speed of 15 m/s. At what horizontal distance between the target and the rocket should you launch?

검증된 단계별 안내
1
Convert the mass of the rocket from grams to kilograms: \( m = 800 \, \text{g} = 0.8 \, \text{kg} \).
Calculate the net force acting on the rocket using \( F_{\text{net}} = F_{\text{thrust}} - F_{\text{gravity}} \), where \( F_{\text{gravity}} = m \cdot g \) and \( g = 9.8 \, \text{m/s}^2 \).
Determine the rocket's acceleration using Newton's second law: \( a = \frac{F_{\text{net}}}{m} \).
Use the kinematic equation \( h = \frac{1}{2} a t^2 \) to solve for the time \( t \) it takes for the rocket to reach the height of 30 m. Rearrange the equation to \( t = \sqrt{\frac{2h}{a}} \).
Calculate the horizontal distance the target travels during the time \( t \) using \( d = v \cdot t \), where \( v = 15 \, \text{m/s} \). This distance is the horizontal separation at which the rocket should be launched.

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.

Newton's Second Law of Motion

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. This principle is crucial for understanding how the rocket will accelerate upwards under the influence of the thrust provided by its engine, allowing us to calculate its motion over time.
추천 영상:
가이드 코스
06:54
Intro to Forces & Newton's Second Law

Projectile Motion

Projectile motion refers to the motion of an object that is launched into the air and is subject to gravitational force. In this scenario, the rocket's vertical motion can be analyzed as a projectile, allowing us to determine how long it will take to reach the target's height of 30 m, which is essential for calculating the horizontal distance needed for the launch.
추천 영상:
가이드 코스
04:44
Introduction to Projectile Motion

Relative Velocity

Relative velocity is the velocity of an object as observed from another moving object. In this problem, understanding the relative velocity between the rocket and the target is key to determining the correct launch distance, as the target is moving horizontally while the rocket ascends vertically, necessitating a calculation of their positions over time.
추천 영상:
가이드 코스
04:27
Intro to Relative Motion (Relative Velocity)