Purpose: Using energy methods, calculate the coefficient of friction between woo

Question

Purpose:

Using energy methods, calculate the coefficient of friction between wood and a flat ramp.

Derive:

Derive a function that gives the coefficient of kinetic friction between the block and the track in terms of the masses and the acceleration. You must work fundamentally (though not necessarily exclusively) from energy principles (like the Work-Energy Theorem), not from Newton’s Laws. Show your work, including a force diagram for the system (don’t include internal forces!), and your algebra with symbols only – no numbers in the algebra!

What is the deeper evidence of the model’s applicability?

Explanation / Answer

let mass on the track be M and hanging mass be m.

let coefficient of kinetic friction be k .

let acceleration of the system be a.

if the block with mass m moves down a distance of h,

then speed achieved by mass M=sqrt(2*a*h)

normal force=M*g

friction force=k*M*g

using work energy principle:

initial potential energy+initial kinetic energy-work done by friction=final potential energy + final kinetic energy

==>0+0-k*M*g*h=-m*g*h+0.5*(M+m)*v^2=-m*g*h+0.5*(M+m)*2*a*h

==>k*M*g*h=m*g*h-(M+m)*a*h

==>k=(m*g-(m+M)*a)/(M*g)

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.