MHB Challenging Classical Mechanics Problems: Can You Solve Them?

AI Thread Summary
The discussion focuses on solving two classical mechanics problems involving motion up and down an incline with kinetic friction. Key equations are provided for calculating distance and time, incorporating initial and final velocities, acceleration due to gravity, and friction. The second problem relates to d'Alembert's principle, emphasizing the use of fictitious forces in non-inertial frames to equate dynamics between different systems. The participant expresses gratitude for the assistance received, indicating that the help will aid in tackling similar problems. Overall, the thread highlights the challenges of applying classical mechanics concepts to specific scenarios.
johnherald
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Hello i have the difficulty in solving this two problems..thank you for your help math help boards :-) View attachment 8748
 

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1.6

distance up the incline (with kinetic friction present) ...

$\Delta x = \dfrac{v_f^2 - v_0^2}{2a}$

time up the incline ...

$t = \dfrac{v_f-v_0}{a}$

... where $v_f=0$ and $a = -g(\sin{\theta} + \mu \cos{\theta})$time down the incline ...

$\Delta x = v_0 \cdot t + \dfrac{1}{2}at^2 \implies t = \sqrt{\dfrac{2\Delta x}{a}}$

note $v_0 = 0$, $\Delta x$ is the opposite of that found going up the incline and $a = -g(\sin{\theta} - \mu \cos{\theta})$
 
1.5 is related to d'Alembert's principle. We can analyze the dynamics of an accelerating frame of reference (i.e non-inertial) by adding a fictitious force. Since the force in system A is $m*100$, then a fictitious force of $m*10$ must be added to system B so that the dynamics in both systems are equivalent.
 
thanks a lot that will help me solving the other problems similar to that two particular question...:-)
and i have the difficulty solving some problems specially to the questions without a value.. thank you again for your help..
 
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