Answer:
Explanation:
Conduction of heat through a thick layer is governed by the following relation
Q = KA( T₂ -T₁ ) / d
K is thermal conductivity of medium ( it is earth here ) , A is surface area though which heat conducts and T₂ -T₁ is temperature difference and d is thickness of medium through which heat conducts.
k = 8 units
A = surface area= 2πrL
= 2x 3.14 x 2/12 x 100
= 104.67 ft²
T₂ -T₁ = 70 - 42
= 28 F
d = thickness
= 30 /12 ft
= 2.5 ft
Putting the given values here
Q =
= 9378.4 Btu per hour.
Answer:
I'm pretty sure it's 37.5 joules of energy
Explanation:
hope this helps!
The rotational speed of the two children is the same.
In fact, it is defined as
where
is the angle covered in the time
. As it can be seen, this quantity does not depend on the distance from the centre, so the rotational speed is 4.0 revolutions per minute for both children.
To calculate the gravitational force acting on an object given the mass and the acceleration due to gravity, use the following formula.
Fg = m • g
Fg = 1.3 kg • 9.8 m/s^2
Fg = 12.74 N or about 12.7 N.
The solution is C. 12.7 N.