Mechanics11/Seite9/Loesung3.4

a) a = [math]\frac{v}{t}[/math]

daraus folgt:

     a = [math]\frac{45 m/s}{30s}[/math] = 1.5 [math]\frac{m}{s^2}[/math]

b) F = a*m

daraus folgt:

      m = [math]\frac{F}{a}[/math] = [math]\frac{1000 N}{1.5 m/s^2}[/math] = 666.7 kg

c)

      m' = 1.5 * m = 666.7 kg * 1.5 = 1000 kg

      a = [math]\frac{F}{m}[/math] = [math]\frac{1000 N}{1000 kg}[/math] = 1.0 [math]\frac{m}{s^2}[/math]

       v = a*t = 1.0 [math]\frac{m}{s^2}[/math] * 30s = 30 [math]\frac{m}{s}[/math]

Schülerlösung

geg: t=30s F=1000N v = 45 m/s

a) ges: a

v = a * t

a = [math]\frac {v}{t}[/math]

a = [math]\frac {45m/s}{30s}[/math]

a = 1,5 [math]\frac {m}{s^2}[/math]

b) ges: m

F = m * a

m = [math]\frac {F}{a}[/math]

m = [math]\frac {1000}{1,5m/s^2}[/math]

m = 666,66kg = 0,67t

c)

a = [math]\frac {F}{m}[/math]

v = a * t = [math]\frac{F}{m}[/math] * t

v = [math]\frac {1000N}{1,5 * 667kg}[/math] * 30s = 29,985 m/s

von Natalia Dobrzycka 11B