Pmli

TALLER 1

1)

2)
319 kWh*1000 W1 kW=319000 Jsh
319000 Jsh*3600 s1 h=1148400000 J

319 kWh=1.1484*109 J1.1484*109 J*1000 cal4186.8 J=274290627.7 cal

319 kWh=274.29*106 cal

3)
W=200 J
e=30%
QA= ?
QB= ?

A)
e=WQA
QA=WeQA=200 J0.3

QA=666,67 J

B)
QA=W+QB
QA-W=QB
666.67 J-200 J=QB

QB=466.67 J

4)
m=1.6*10-27 kg
d=6 mt=1.8*10-4 s
V=dt
V=6 m1.8*10-4 s
V=33.33*103 ms

EK=12*m*V2
EK=12*1.6*10-27 kg*33.33*103 ms2
EK=8.88*10-19 J
8.88*10-19J*1 eV1.602*10-19 J=5.54 eV

EK=5.54 eV

5)
m=75 kg
t=30 s
d=10 m
a=g=9.8 ms2
A)
F=m*a
F=75 kg*9.8 ms2
F=735N

W=F*d
W=735 N*10 m

W=7350 J

B)
P=Wt
P=7350 J30 s

P=245 W

6)
m=75*103g=75 kg
h=0.065 km=65 m
g=9.8ms2

A)
Epg=m*g*h
Epg=75 kg*9.8 ms2*65 m

Epg=47.775*103 J

B)
Eki+Epi=Ekf+EPf
12*m*Vi2+m*g*hi=12*m*Vf2+m*g*hf2*g*hi-hf=Vf2
Vf2=2*9.8 ms2*65 m-30 m
Vf2=686 m2s2
Vf=26.19 ms

ET=Ek+EP
ET=12*m*V2+m*g*h
ET=12*75 kg*26.19 ms2+75kg*9.8 ms2*30 m
ET=47.77*103 J

47.77*103 J*2.77*10-4 Wh1 J=13.23 Wh

ET=13.23 Wh

C)
ET=EPgi+EPgfET=m*g*hi-m*g*hf
ET=m*g*hi-hf
ET=75 kg*9.8 ms2*65 m-0 m
ET=47.77*103 J

47.77*103 J*2.77*10-4 Wh1 J=13.23 Wh

ET=13.23 Wh