$1.$ For the $4-$bar linkage below, determine the following:

a$.$ Whether or not it is a Grashof mechanism

b$.$ Whether or not any link can undergo a full rotation

c$.$ If it is a class $1,2$ or $3$ kinematic chain

d$.$ What type of mechanism it is $($crank$-$rocker, triple$-$rocker, etc.$)$

The mechanism is not drawn to scale. The input is link $2,$ the output is link $4$ and link $1$ is the

ground. Link $1$ is the imaginary line drawn between points $O_2$ and $O_4.$

$2.$ What is a possible reason why a slider joint may experience excessive or accelerated wear during

operation?