4. (15 points) The dimensions of this offset slider-crank mechanism are: AB=20mm, \(e=\)10mm, BC=70mm. Please use graphical to find out: 1) the length H of slider stroke. 2) if the crank acts as driving link, find out the minimum value of the transmission angle \(\gamma\) of this mechanism. 3) If the slider acts as driving link, find out the dead point position of this mechanism.
5. (20 points) Determine module m, number of teeth z, nominal pitch circle diameter d, dedendum circle diameter $d_y$, pitch p of standard involute straight spur gear with external contact, if dedendum of a tooth $h_y$=5 mm, addendum circle diameter $d_a$=108 mm.
6. (25 points) Determine velocity ratio $\omega_{21}$ and rotational speeds $n_2$ if $n_1$=5 rpm; $z_1$=20; $z_2$=?