/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 72 Three forces act on a particle t... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Three forces act on a particle that moves with unchanging velocity \(\vec{v}=(2 \mathrm{~m} / \mathrm{s}) \hat{\mathrm{i}}-(7 \mathrm{~m} / \mathrm{s}) \hat{\mathrm{j}} .\) Two of the forces are \(\vec{F}_{1}=(2 \mathrm{~N}) \hat{\mathrm{i}}+\) \((3 \mathrm{~N}) \hat{\mathrm{j}}+(-2 \mathrm{~N}) \hat{\mathrm{k}}\) and \(\vec{F}_{2}=(-5 \mathrm{~N}) \hat{\mathrm{i}}+(8 \mathrm{~N}) \hat{\mathrm{j}}+(-2 \mathrm{~N}) \hat{\mathrm{k}} .\) What is the third force?

Short Answer

Expert verified
\( \vec{F}_{3} = (3 \mathrm{~N}) \hat{i} - (11 \mathrm{~N}) \hat{j} + (4 \mathrm{~N}) \hat{k} \).

Step by step solution

01

Understand the problem

The problem involves three forces acting on a particle. The particle is moving with a constant velocity, which implies that the net force on it must be zero. We need to find the third force given two of them.
02

Recall the condition for constant velocity

A constant velocity implies zero acceleration. According to Newton's second law, if there is zero acceleration, the net force acting on the particle must be zero: \( \vec{F}_{net} = \vec{0} \).
03

Express the net force equation

Write the equation for the net force as the sum of the three forces: \( \vec{F}_{1} + \vec{F}_{2} + \vec{F}_{3} = \vec{0} \). Our task is to solve this equation for \( \vec{F}_{3} \).
04

Rearrange to find the third force

Rearrange the equation from Step 3 to isolate \( \vec{F}_{3} \): \( \vec{F}_{3} = - (\vec{F}_{1} + \vec{F}_{2}) \).
05

Calculate \( \vec{F}_{1} + \vec{F}_{2} \)

Add vectors \( \vec{F}_{1} \) and \( \vec{F}_{2} \) component-wise: - For \( \hat{i} \) component: \( 2 + (-5) = -3 \) - For \( \hat{j} \) component: \( 3 + 8 = 11 \) - For \( \hat{k} \) component: \( -2 + (-2) = -4 \) Therefore, \( \vec{F}_{1} + \vec{F}_{2} = (-3 \mathrm{~N}) \hat{i} + (11 \mathrm{~N}) \hat{j} + (-4 \mathrm{~N}) \hat{k} \).
06

Determine \( \vec{F}_{3} \)

Using the result from Step 5, we find \( \vec{F}_{3} = - (-3 \mathrm{~N}) \hat{i} - (11 \mathrm{~N}) \hat{j} - (-4 \mathrm{~N}) \hat{k} = (3 \mathrm{~N}) \hat{i} - (11 \mathrm{~N}) \hat{j} + (4 \mathrm{~N}) \hat{k} \).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

constant velocity
When a particle has a constant velocity, it means that the speed and direction of its movement do not change over time.
In physical terms, this suggests that the particle experiences no net acceleration.
According to Newton's Second Law of Motion, net force and acceleration are closely related, stated as \( F = ma \).
Here, \( F \) represents the net force applied, \( m \) is mass, and \( a \) is acceleration.- If acceleration \( a = 0 \), the net force \( F \) must be zero.
- This condition of zero net force confirms that all acting forces are balanced, maintaining the constant velocity.A particle moving at a constant velocity reflects equilibrium among all external forces.
In the exercise, this principle helps us understand that the sum of all vectors acting upon the particle is zero.
This understanding is crucial in determining the missing force needed for balance.
net force
Net force is essentially the vector sum of all forces acting on a particle or body.
To put it another way, it defines how much a group of forces will influence the motion of an object.
For an object at constant velocity, the net force is zero, meaning all forces cancel each other out.- Net force \( \vec{F}_{net} = \vec{F}_1 + \vec{F}_2 + \vec{F}_3 + \ldots \)- This means the total of each force's magnitude and direction is accounted for.
In the problem exercise, the net force is zero because the particle moves with constant velocity.
By using the formula \( \vec{F}_{net} = \vec{0} \), we can deduce that the sum of known forces and the unknown force must be equal to zero.
This simplifies our task to ensure that all known forces are effectively cancelled by the third force we're trying to find.
vector addition
Vector addition is a mathematical tool to combine forces, which are vector quantities.
This method considers both direction and magnitude.
Each vector is broken into its components, typically alongside the Cartesian axes—\( \hat{i}, \hat{j}, \hat{k} \).- Add each corresponding component together: - \( i \) components add to \( i \) components. - \( j \) components add to \( j \) components. - \( k \) components add to \( k \) components.
For example, if you have two forces:
- \( \vec{A} = a_i \hat{i} + a_j \hat{j} + a_k \hat{k} \)- \( \vec{B} = b_i \hat{i} + b_j \hat{j} + b_k \hat{k} \)- Then the sum, \( \vec{A} + \vec{B} = (a_i + b_i) \hat{i} + (a_j + b_j) \hat{j} + (a_k + b_k) \hat{k} \)In our problem scenario, vector addition is used to combine the known forces \( \vec{F}_1 \) and \( \vec{F}_2 \) to find the missing \( \vec{F}_3 \) needed to maintain the net force of zero.
Understanding the process of vector addition ensures accurate computation of resultant forces in multidimensional spaces.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A certain force gives an object of mass \(m_{1}\) an acceleration of \(12.0 \mathrm{~m} / \mathrm{s}^{2}\) and an object of mass \(m_{2}\) an acceleration of \(3.30 \mathrm{~m} / \mathrm{s}^{2} .\) What acceleration would the force give to an object of \(\operatorname{mass}(\mathrm{a}) m_{2}-m_{1}\) and (b) \(m_{2}+m_{1} ?\)

A \(40 \mathrm{~kg}\) skier skis directly down a frictionless slope angled at \(10^{\circ}\) to the horizontal. Assume the skier moves in the negative direction of an \(x\) axis along the slope. A wind force with component \(F_{x}\) acts on the skier. What is \(F_{x}\) if the magnitude of the skier's velocity is (a) constant, (b) increasing at a rate of \(1.0 \mathrm{~m} / \mathrm{s}^{2},\) and (c) increasing at a rate of \(2.0 \mathrm{~m} / \mathrm{s}^{2} ?\)

A \(500 \mathrm{~kg}\) rocket sled can be accelerated at a constant rate from rest to \(1600 \mathrm{~km} / \mathrm{h}\) in \(1.8 \mathrm{~s}\). What is the magnitude of the required net force?

The high-speed winds around a tornado can drive projectiles into trees, building walls, and even metal traffic signs. In a laboratory simulation, a standard wood toothpick was shot by pneumatic gun into an oak branch. The toothpick's mass was \(0.13 \mathrm{~g}\), its speed before entering the branch was \(220 \mathrm{~m} / \mathrm{s},\) and its penetration depth was \(15 \mathrm{~mm} .\) If its speed was decreased at a uniform rate, what was the magnitude of the force of the branch on the toothpick?

A lamp hangs vertically from a cord in a descending elevator that decelerates at \(2.4 \mathrm{~m} / \mathrm{s}^{2}\). (a) If the tension in the cord is \(89 \mathrm{~N},\) what is the lamp's mass? (b) What is the cord's tension when the elevator ascends with an upward acceleration of \(2.4 \mathrm{~m} / \mathrm{s}^{2} ?\)

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.