# Awdawdawd Essay

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214. F = 0,5 N m = 0,5 kg µ = ? Ftr = µ * N µ = Ftr / m*g µ = 0,5 N / 5 N µ = 0,1 N 215. m = 5 kg F = 13 N a = 2,5 m/s2 µ = ? m * a = F - µ * N 0 = N - m * g N = 50 N 12,5 = 13 - µ * 50 50 µ = 0,5 µ = 0,01 216. m = 2 kg µ = 0,06 t = 1 s F = 1,8 N s = ? m * a = F - Ftr Ftr = µ * N 0 = N - m * g N = m * g m * a = F - µ * N m * a = F - µ * m * g / :m a = F/m - µ *g a = 1,8/2 - 0,06 * 10 a = 0,9 - 0,6 a = 0,3 m/s2 s = a*t2 / 2 s = 0,32 / 2 s = 0,15 m 217. m1 = 1 kg m2 = 2 kg F = 18 N µ = 0,3 a = ? m1 * a = F - t - µ * m * g m2 * a = F - t - µ * m * g a = F / (m1 + m2) - µ * g a = 3 m/s2 288. F1 = 2 N F2 = 3 N F3 = 5 N Sile treba da budu istog pravca. Sile od 2 i 3 N treba da budu jednog smera, a od 5 N suprotnog. 289. Moze li telo biti u ravnotezi: a) F1 = 20 N, F2 = 20 N - moze b) F1 = 20 N, F2 = 15N - ne c) F1 = 20 N, F2 = 20 N - ne 290. m = 100 kg αlfa = 90 0 T (sila zatezanja) = ? T = m*g / √2 T = 1000 / √2 T = 709,21 N 295. m1 = 10 kg m2 = 5 kg l = l / 4 N (sila reakcije) = ? / * 4 Nb*l - m1*g* l/2 -m2*g* l/4 = 0 4Nbl - 2m1g * l - m2gl = 0 / : l 4Nb - 2m1g - m2g = 0 4Nb = 2m1g + m2g 4Nb = 2*10*10 + 5*10 4Nb = 250 Nb = 62,5 N Na = m1g + m2g -Nb Na = 150 - 62,5 Na = 87,5 N 296. l1 = 4 m l2 = 1 m F = 150 N N = ? Nb*l1 - F*l2 = 0 4Nb - F = 0 Nb = 37,5 N Na - F + Nb = 0 | Na = F - Nb Na = 112,5 N 347. R = 6400 km h = ? F/100F = ɣ((mz+mb)/(Rz+h)2) / ... (ɣ*mz*mb) / (Rz2) 1 / 100 = Rz2 / (Rz + h)2 (Rz + h)2 = 100 Rz2 Rz + h = 10 Rz h = 10 Rz - Rz = 9 Rz H = 57600 km 348. a) Rzs : Rps = 1 : 40 Fzs : Fps = ? Rps = 40 Rzs = 1 Fzs : Fps = ɣ((mz+ms)/Rzs2) / ... ((ɣ*mp*ms)/Rps2) Fzs : Fps = Rps2 / Rzs2 Fzs : Fps = 1600 : 1 348. b) Rm = 1/2 * Rz mm = 1/10 * mz Fz : Fm = ? 349. a) M = 2 * 10-11 kg R = 6,95 * 108 m ɣ = 6,67 * 10-11 a = ? 365. N = ? a) V = 5 m/s na gore