(1)足浴器的电热丝电阻是多大?
(2)足浴器将质量为4kg、初温为20℃的水加热至45℃,水吸收的热量是多少?[水的比热容c水=4.2×103J/(kg•℃)]
(3)若晚上用电高峰时的实际电压只有200V,足浴器加热上述的水需要工作多长时间?(电热丝电阻不变,不计热量损失)
同类型试题
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2