A light spring of force constant 4.35 N/m is compressed by 8.00 cm and held betw

Question

A light spring of force constant4.35N/m is compressed by 8.00 cm and held between a 0.250 kg block on the left and a0.480kg block on the right. Both blocks are at rest on a horizontal surface. The blocks are released simultaneously so that the spring tends to push them apart. Find the maximum velocity each block attains if the coefficient of kinetic friction between each block and the surface is the following. In each case, assume that the coefficient of static friction is greater than the coefficient of kinetic friction. Let the positive direction point to the right.

IF I SEE THE SAME COPY PASTE I'VE SEEN ALL AROUND I WILL REPORT YOU AND YOU WILL BE BANNED. THE WORK MUST BE ORIGINAL AND MUST USE THE NUMBERS FROM >>>>THIS<<<< PROBLEM. I HAVE REPORTED 4 PEOPLE ALREADY TODAY DUE TO COPY PASTE.

THIS IS MY THIRD TIME ASKING THIS QUESTION. NO CREDIT WILL BE GIVEN UNLESS ANSWERS USING >>>THE NUMBERS FROM THIS SPECIFIC PROBLEM<<< ARE GIVEN.

Explanation / Answer

m1V1=m2V2 except V1 and V2 are in opposite directions m1 = 0.250kg m2 = 0.480kg m1V1=m2V2 => V1 = 1.92V2 energy stored in the spring is 0.5*4.35*0.08^2 = 13.92 mJ Without friction 13.92e-3 = (1/2)m1V1^2 + (1/2)m2V2^2 => 0.5*m1(V1^2 + 1.92*V2^2) 13.92e-3 = 0.125[(1.92V2)^2 + 1.92V2^2)] V2 = 0.705m/s V1 = 1.35m/s These numbers do work in m1V1=m2V2 and (1/2)*4.35*.08^2=0.5[m1V1^2+m2V2^2] With Friction Conservation of Momentum must still hold so m1V1=m2V2 => V1=1.92V2 at t = 0 The work done by friction will sum to the energy in the spring = 13.92mJ The initial velocities will be the same but will quickly decrease to zero due to friction Later: suddenly occurred to me that there is not enough force in the compressed spring to over come the friction force holding the 0.480kg block in place. That force = 0.48*9.8*0.1 = 0.47N at least. If F=kx = 4.35*0.08 = 0.348N meaning the larger block would remain stationary and only the 0.25kg block would move. So the energy in the compressed spring would be transfered to the smaller block and 13.92mJ = 0.5*0.25*V^2 => V = 0.3224m/s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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