Answer:
0.763 m
Explanation:
Intensity I = power P ÷ area A of exposure (spherical area of propagation)
I = P/A
A = P/I
Power = 10.0 W
Intensity = 1.39 W/m^2
A = 10/1.39 = 7.19 m^2
Area A = 4¶r^2
7.19 = 4 x 3.142 x r^2
7.19 = 12.568r^2
r^2 = 7.19/12.568 = 0.57
r = 0.753 m
Answer:
<h2> $1.50</h2>
Explanation:
Given data
power P= 2 kW
time t= 15 min to hours = 15/60= 1/4 h
cost of power consumption per kWh= 10 cent = $0.1
We are expected to compute the cost of operating the heater for 30 days
but let us computer the energy consumption for one day
Energy of heater for one day= 2* 1/4 = 0.5 kWh
the cost of operating the heater for 30 days= 0.5*0.1*30= $1.50
<u><em>Hence it will cost $1.50 for 30 days operation</em></u>
Answer:
cal
Explanation:
= mass of ice = 100 g = 0.1 kg
= specific heat of ice = 0.5 cal/(kg°C)
= specific heat of water = 1 cal/(kg°C)
= Latent heat of fusion of ice = 80 J/g
= initial temperature of ice = - 20 °C
= final temperature of ice = 50 °C
Q = Heat gained
Heat gained is given as
cal
