Let h = the thickness of ice, m.
Because the ice covers an area of 0.65 m², the volume of ice is
V = 0.65h m³
The density of ice is 917 kg/m³, therefore the mass of ice is
m = (917 kg/m³)*(0.65h m³) = 596.05h kg
The latent heat of fusion of ice is 3.35 x 10⁵ J/kg, therefore the heat required to melt the ice is
Q₁ = (596.05h kg)*(3.35 x 10⁵ J/kg) = 2h x 10⁸ J
The electric heater supplies heat at 12 V, 23 A for 4.3 minutes to melt the ice.
Therefore the heat provided is
Q₂ = (12 V)*(23 A)*(4.3*60 s) = 71208 J
Because Q₁ = Q₂, obtain
2h x 10⁸ = 71208
h = 356 x 10⁻⁶ m = 356 x 10⁻³ mm = 0.356 mm
Answer: 0.356 mm
I believe the correct answer from the choices listed above is the third option. <span>The force exerted by the book on the table is equal to the force exerted by the table which is 4.0 N. The book does not move so it must be that the forces are balanced. Hope this answers the question.</span>
Answer:
The correct answer - c. 12.
Explanation:
Given:
Total distance: 6 km
Total time - 45 minutes
covered distance - one half of 6 km = 3 km
time used - 2/3*45 = 30 minutes
Solution:
Remaining distance - 6-3 = 3 km
Remaining time = 45 - 30 = 15 minutes or 1/4 hour
Required speed = remaining distance/ remaining time
=
=
= 12 km/hr
A.
accept new and different ideas.