1. m = 5 kg a = 4 m/s^2 μ = 0,5 Fw = m • a Fw = F - T F = Fw + T T = μ • m • g F = m • a + μ • m • g F = m • (a + μ • g) F = 5 • (4 + 0,5 • 10) = 45 N 2. m = 2 kg α = 45* F = 30 N Fw = m • a Fw = Fs + T a = Fw / m a = (Fs + T) / m Fs = sin α • m • g T = μ • cos α • m • g a = g • (sin α + μ • cos α) a = 10 • (sin 45* + 0,2 • cos 45*) = 8,5 m/s^2 3. m1 = 2 kg m2 = 3 kg F = 50 N f = 0,2 a) (do ciała m1) a = Fw / m m = m1 + m2 Fw = F - T T = T1 + T2 T1 + T2 = f • m1 • g + f • m2 • g = f • g • (m1 + m2) Fw = F - f • g • (m1 + m2) a = [F - f • g • (m1 + m2)] / (m1 + m2) Fn = m1 • {[F - f • g • (m1 + m2)] / (m1 + m2)} Fn = 2 • {[50 - 0,2 • 10 • (2 + 3)] / (2 + 3)} Fn = 16 N b) (do ciała m2) Fn = m2 • {[F - f • g • (m1 + m2)] / (m1 + m2)} Fn = 3 • {[50 - 0,2 • 10 • (2 + 3)] / (2 + 3)} Fn = 24 N 4. m = 4 kg F = 20 N a = 3 m/s^2 f = ? Fw = m • a Fw = F - T T = f • m • g Fw = F - f • m • g m • a = F - f • m • g f = (F - m • a) / (m • g) f = (20 - 4 • 3) / (4 • 10) f = 0,2 5. m1 = 1 kg m2 = 2 kg f = 0,3 a) (zwisa ciało m1) a = Fw / m a = (m1 • g - f • m2 • g) / (m1 + m2) Fn = m1 • g - m1 • {[g • (m1 - f • m2)] / (m1 + m2)} Fn = 1 • 10 - 1 • {[10 • (1 - 0,3 • 2)] / (1 + 2)} Fn = 8,67 N b) (zwisa ciało m2) Fn = m2 • g - m2 • {[g • (m2 - f • m1)] / (m1 + m2)} Fn = 2 • 10 - 2 • {[10 • (2 - 0,3 • 1)] / (1 + 2)} Fn = 8,67 N
1. m = 5 kg a = 4 m/s^2 μ = 0,5 Fw = m * a Fw = F - T F = Fw + T T = μ * m * g F = m * a + μ * m * g F = m * (a + μ * g) F = 5 (4 + 0,5 * 10) = 45 N 2. m = 2 kg α = 45* F = 30 N Fw = m * a Fw = Fs + T a = Fw / m a = (Fs + T) / m Fs = sin αmg T = μ * cos α m g a = g * (sin α + μ * cos α) a = 10 * (sin 45* + 0,2 * cos 45*) = 8,5 m/s^2 3. m1 = 2 kg m2 = 3 kg F = 50 N f = 0,2 a) (do ciała m1) a = Fw / m m = m1 + m2 Fw = F - T T = T1 + T2 T1 + T2 = f * m1 *g + f * g = f * g *(m1 + m2) Fw = F - f * g *(m1 + m2) a = [F - f *g *(m1 + m2)] / (m1 + m2) Fn = m1 * {[F - f * g * (m1 + m2)] / (m1 + m2)} Fn = 2 *{[50 - 0,2 *10 * (2 + 3)] / (2 + 3)} Fn = 16 N b) (do ciała m2) Fn = 3 * {[50 - 0,2 *10 *(2 + 3)] / (2 + 3)} Fn = 24 N 4. m = 4 kg F = 20 N a = 3 m/s^2 f = ? Fw = m *a Fw = F - T T = f *m *g Fw = F - f *m *g m *a = F - f *m *g f = (F - m *a) / (m *g) f = (20 - 4 *3) / (4 *10) f = 0,2 5. m1=1 kg m2=2 kg f = 0,3 a) (zwisa ciało m1) a = Fw / m a = (m1 * g - f *m2 *g) / (m1 + m2) Fn = m1 *g - m1 *{[g *(m1 - f *m2)] / (m1 + m2)} Fn = 1 *10 - 1 *{[10 *(1 - 0,3 *2)] / (1 + 2)} Fn = 8,67 N b) (zwisa ciało m2) Fn = m2 *g - m2 *{[g *(m2 - f *m1)] / (m1 + m2)} Fn = 2 *10 - 2 *{[10 *(2 - 0,3 *1)] / (1 + 2)} Fn = 8,67 N coś w 5 mi się lekko nie zgadzało, miałam wątpliwości, ale teraz widzę , że chyba jest ok, bo mój poprzednik też tak miał . Pozdro. ;)
