WAEC - Physics (1990 - No. 49)
How long will it take to heat 3 kg of water from 28oC to 88oC in an electric taking a current of 6 A from an e.m.f. source of 220V?
96s
1.20s
570s
600s
1200s
Giải thích
Ivt = mcΔθ
t =
mcΔθIv
= 3x 4200 x (88 - 28)6 x 200