Oct 5, 2011 #1 S School New member Joined Mar 10, 2010 Messages 5 Reaction score 0 Points 1 to the ground? .? i need to find k= (it has to be in j)
Oct 7, 2011 #2 H hit1 Member Joined Jul 8, 2008 Messages 83 Reaction score 0 Points 6 Perform an Energy Balance: dU+dEp+dEk=Q+W dU,dEp,Q, and W are negligible thus dEk = 0. The definition of Ek= 1/2mv^2 thus Ek(2)=Ek(1) which means you just solve fo Ek(1) to get you the kinetic energy. Ek(1)=1/2(2.4E5 kg)((900 km/h)*(1000(m/km)/3600(s/h)))^2 = 7,500,000,000 J As you can see I did the calculation converting the amount of km to meters then the hours to seconds since the definition of joules is kg/m^2*s^2 not kg/km^2*h^2
Perform an Energy Balance: dU+dEp+dEk=Q+W dU,dEp,Q, and W are negligible thus dEk = 0. The definition of Ek= 1/2mv^2 thus Ek(2)=Ek(1) which means you just solve fo Ek(1) to get you the kinetic energy. Ek(1)=1/2(2.4E5 kg)((900 km/h)*(1000(m/km)/3600(s/h)))^2 = 7,500,000,000 J As you can see I did the calculation converting the amount of km to meters then the hours to seconds since the definition of joules is kg/m^2*s^2 not kg/km^2*h^2