Question

click for figure1 https://www.hizliresim.com/94cfjfb

A 1.5-kg

kg block rests on top of a 7.5-kg

kg block. The cord and pulley have negligible mass, and there is no significant friction anywhere.

a)What force F

F must be applied to the bottom block so the top block accelerates to the right at 2.2 m/s

2

m/s2 ?

b)What is the tension in the connecting cord?

Answer 1

a) The bottom block is the combination of the two masses ;

$M=7.5+1.5=9kg$

Therefore the force applied is $F=ma$

$F=9×2.2=19.8N$

b) The tension $T$ in the string is ;

$T=1.5×2.2=3.3N$