In problem 17p on chapter 5, they are asking tofind the magnitude of the contact force between boxes 1 and 2and between boxes 2 and 3. On step 3 in solution, you added twomasses(m2 and m3) and multiplied by force 7.50. but why you didntadd mass 1 and mass 2 in stap 2? you used only mass 1 andmultiplied by force. can you please explain? Thank you In problem 17p on chapter 5, they are asking tofind the magnitude of the contact force between boxes 1 and 2and between boxes 2 and 3. On step 3 in solution, you added twomasses(m2 and m3) and multiplied by force 7.50. but why you didntadd mass 1 and mass 2 in stap 2? you used only mass 1 andmultiplied by force. can you please explain? Thank you
Explanation / Answer
The boxes accelerates together F = (m1 + m2 + m3 ) a or a = F / ( m1 + m2 + m3 ) = 7.50 / ( 1.30 + 3.20 + 4.90 ) = 0.7979 m/s2 (a) The contact force F21 acclecrates box 1 is : F21 = m1 a = 1.30 * 0.7979 = 1.40 N (b) The contact forceF32 accelerates box 1 and 2 . F32 = ( m1 +m2 ) a = ( 1.30 + 3.20 ) ( 0.7979 ) = 3.59 N Hope this helps u!