at the start, Total Energy = mgh = 800g
energy is conserved, so it does not change
oh, you can go through the steps of finding its PE and KE at 60m, but it will come out the same.
PE = 8*60g = 480g
It falls for t = √(80/g) seconds, at which time its velocity is
v = gt = √(80g)
Then its KE = 1/2 mv^2 = 4(√80g)^2 = 320g
PE+KE is still 800g
A BALL OF MASS 8KG FALLS FROM REST FROM A HIGHT OF 100M NEGLECTING AIR RESISTANCE CALCULATE THE TOTAL ENERGY AFTER FALLING A DISTANCE OF 40M
2 answers
TE = Total energy.
TE = PE + KE.
TE = M*g*h + 0 = 8*9.8*100 = 7840 Joules @ 100m.
V^2 = Vo^2 + 2g*d = 0 + 19.6*40 = 784,
V = 28 m/s.
TE = Mgh + KE = 8*9.8*60 + 0.5*8*28^2 = 7840 J. @ 60m.
Yes, there is no change in TE.
TE = PE + KE.
TE = M*g*h + 0 = 8*9.8*100 = 7840 Joules @ 100m.
V^2 = Vo^2 + 2g*d = 0 + 19.6*40 = 784,
V = 28 m/s.
TE = Mgh + KE = 8*9.8*60 + 0.5*8*28^2 = 7840 J. @ 60m.
Yes, there is no change in TE.
21 answers