Blocks of mass 15, 45, and 135 kg are lined up from left to right in that order on a frictionless surface so each block is touching the next one. A rightward-pointing force of magnitude 28 N is applied to the left-most block.

1.)What is the magnitude of the force that the left block exerts on the middle one?

2.)What is the magnitude of the force that the middle block exerts on the left one?

3)What is the magnitude of the force that the middle block exerts on the rightmost one?

4)Now the position of the right two masses is flipped. What is the magnitude of the force that the middle block exerts on the right block?

2 answers

Acceleration of system = 20/(15 + 30 + 120), = 0.1212m/sec^2.
1) Force = (ma) = (120 + 30) x 0.1212, = 18.18N.
2) The same.
3) (30 x 0.1212) = 3.636N.
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Now find four