PHY 1321 Lecture Notes - Lecture 3: Thai Baht, Asteroid Family

• School: University of Ottawa
• Department: Physics
• Course: PHY 1321
• Professor: Andrzej Czajkowski

Document Summary

Applications of newton"s laws (cid:15) sample problems (cid:15) homework. In the (cid:2)gure below, a block b of mass m = 15. 0 kg hangs by a cord from a knot k of mass mk, which hangs from the ceiling by means of two other cords. The cords have negligible mass, and the magnitude of the gravitational force on the knot is negligible compared to the gravita- tional force on the block. Block ) x fy = t3 (cid:0) fg = 0. T3 = fg = m g = (15:0 kg) (cid:18)9:8 m=s2(cid:19) = 147 n. Knot ) x fx = t2 cos 47(cid:14) (cid:0) t1 cos 28(cid:14) = 0. T2 = cos 28(cid:14) cos 47(cid:14)t1 = 1:29t1. X fy = t1 sin 28(cid:14) + t2 sin 47(cid:14) T1 sin 28(cid:14) + (1:29t1) sin 47(cid:14) (cid:0) t3 = 0 (cid:0) t3 = 0. 147 n sin 28(cid:14) + 1:29 sin 47(cid:14) = 104 n.