(1)F=pS=1.10×105Pa×400×10-4m2=4400N,
(2)R1=
U2 |
P1 |
(220V)2 |
800W |
(3)∵R2=2R1,
∴R2=2R1=2×60.5Ω=121Ω,
P2=
U2 |
R2 |
(220V)2 |
121Ω |
W1=P1t1=800W×1800s=1.44×106J,
W2=P2t2=400W×3600s=1.44×106J,
W=W1+W2=1.44×106J+1.44×106J=2.88×106J.
答:(1)壓力是4400N;
(2)R1阻值為60.5Ω;
(3)***消耗2.88×106J電能.