Design a four-bar Grashof crank-rocker that provides limited rocker motion with quick-return action when being driven by a constant crank. The design specifications are:

The output rocker O4Q and must have length L4 = 100 mm, where O4 is pivoted to ground.

The output rocker must have 30° total range of motion, symmetrically about a vertical axis (i. e., 15° on each side).

The coupler with joint P connected to the crank and joint Q connected to the rocker must have length L3 = 150 mm.

The crank O2P must rotate at a constant speed  = 60 rpm.

The time ratio between forward and back action must be 1:1.2.

What are the characteristic crank angles, α,β, δ? What are the lengths of the ground link L1 and the crank connecting O2 and P, L2? Also, please provide two diagrams showing the linkage in each of its extreme positions separately. In other words, one diagram of the mechanism with the rocker as far counterclockwise as it can move, and another diagram of the mechanism with the rocker as far clockwise as it can move.

Please plot the rocker angle (theta 4) vs crank angle (theta 2) for two full crank revolutions (720 degrees) and plot the horizontal position coordinate x of Q v the crank angle (theta 2) for two full crank revolutions (720 degrees).

in a place once known as north america, now known as panem, is a very rich city surrounded by twelve districts. every year because this very rich city, known as the capitol, is so rich and likes to think they control all the districts - which they do - there is something known as the hunger games! this is where two children, one boy and one girl from each district from the ages of twelve to eighteen, have to leave their families and compete in the hunger games, a live event that is aired on tv's all over panem. when katniss everdeen, aged sixteen from district 12, has to volunteer to take the place of her twelve-year-old sister prim after prim's name is called forth to become the 23rd member to compete in the 74th hunger games, she promises to prim that she will win! katniss doesn't believe she's coming out alive - but she's not going down without a fight.

because district 12 is so poor, katniss has been close to death many times from starvation but she's made it through it. but this is a different kind of close to death; this katniss doesn't know if she can survive.

she doesn't want to hurt, or kill anyone but when it comes down to it katniss' instinct is to survive. but when she starts to have confusing feelings about the boy from her district who is also her fellow contender, things get worse, and then she teams up with the girl from district 11 and only one person can survive. but who will it be? will her feelings get the better of her? will she let someone else win so they don't have to die? if katniss is going to win she's going to have to be brutal. she's going to have to kill!

it is important so later on in life they . can solve issues like that or other tough times in their life.. and also have info on those topics.

they can talk about topics like that by sitting the person down and talking with them.

explanation:

i believe the answer is b.