Please help me for number 3 I really need it

What difference(s) did you notice using a pneumatic circuit over hydraulic circuit.explain why the pneumatic piston stumbles when it hits an obstacle.

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?

Ifa component is made of two or more materials with different modulus of elasticity (e), it is called a composite member and we calculate the factor·n". mention the formula for calculating n". also, ifn> 1, explain what will happen to the 1. transformed.gi) ifn 1, what will happen to the material when transformed material when