Question

Insert Design Layout References Mailings Review View Help А. An 80 kg construction worker sits down 2.0 m from the left end of a 1450 kg beam to eat lunch. The cable supporting the beam can have a tension of 15,000 N-but no higher without breaking. You need to figure out if the worker is safe. 30° 2m 4m 1. Draw a diagram that shows all the forces on the beam and where they act. (There are four forces.) 2 Which of those forces do you need to calculate in order to decide whether the beam is safe or unsafe? 3. Is there one force that you know must less about than other forces? And is that a force that you do not need to calculate in order to answer the question? If so, that tells you where the most convenient, sensible place is for the pivot point (or reference point). Find that location. Either show in the force diagram where the pivot point is or describe in words where it is. 3. For each of the four forces, find the torque. If you have enough numerical information calculate its value. If you do not, write an algebraic expression that has both numbers and variable names for its factors. People often want to misuse given numbers to insert numbers into the equation in places where, in fact, you don't know the number. Don't be one of those people. If there is a factor whose value you don't know, use an algebraic variable. And note that this time, you have a sing factor that is not sin90° Be sure you include the correct sign for each torque. tut EL 4 Write the algebraic expression that shows how the torques you wrote in part 3 combine to produce the net torque. You know the value of the net torque, so set the expression equal to that value. Use the resulting equation to calculate the magnitude of the force that you are looking for.

Answer 1

(2) . Tension force need to Calculate 7 Tsinde Wall force (fo) Pivot 0 at the point of wall is most convenient sensible place. Fio * Tasce &x mg Mog L (nys Ez about pointo. Tworker mgr, a - 80X9.8*2 = -1568 Nom Z beam = -1450x9.8% (244) -42630 Nom 2 Tension + Tsino (2+4) + 337 Nom Twall 3(T) -1568 – 42630 =0 T. 14732.67 SI Tsince (1) - mgx - Mag (t = 0 TE 14732.67 N < 1000 3 so, beam is safe