Answer:
circumference= 65/3 cm = 21.67 cm
radius R = 3.45 cm
Explanation:
To calculate the length of the circumference of the cylinder, we divide 650 cm by 30 (the number of times it wrapped exactly around it)
length of circumference= 65/3 cm = 21.67 cm
now use the formula of the circumference length to find the radius (R):
circumference length = 2 * pi * R
65/3 = 2 * pi * R
R = 65 / (6 pi)
R = 3.45 cm
The answer is B, because it will lose potential energy.
Answer:
Q = - 4312 W = - 4.312 KW
Explanation:
The rate of heat of the concrete slab can be calculated through Fourier's Law of heat conduction. The formula of the Fourier's Law of heat conduction is as follows:
Q = - kA dt/dx
Integrating from one side of the slab to other along the thickness dimension, we get:
Q = - kA(T₂ - T₁)/L
Q = kA(T₁ - T₂)/t
where,
Q = Rate of Heat Loss = ?
k = thermal conductivity = 1.4 W/m.k
A = Surface Area = (11 m)(8 m) = 88 m²
T₁ = Temperature of Bottom Surface = 10°C
T₂ = Temperature of Top Surface = 17° C
t = Thickness of Slab = 0.2 m
Therefore,
Q = (1.4 W/m.k)(88 m²)(10°C - 17°C)/0.2 m
<u>Q = - 4312 W = - 4.312 KW</u>
<u>Here, negative sign shows the loss of heat.</u>