Chapter 4 - Force and Motion - Learning Path Questions and Exercises - Exercises - Page 138: 59

a). $97.5N$ b). $82.5N$

a). $F_{2}-F_{1}=(m_{1}+m_{2})a$ $F_{2}=F_{1}+(m_{1}+m_{2})a$ $F_{2}=(75+(5+10)\times1.5)N=97.5N$ b). $N_{1}=F_{1}+m_{1}a=[75+(5\times1.5)]N=82.5N$ Also, $N_{2}=F_{2}-m_{2}a=[97.5-(10\times1.5)]N=82.5N$ Hence, the force of contact N between the two blocks is $82.5N$