Answer:
a) -3.267 m/s
b) 2.227 m/s
Explanation:
As per the conservation of momentum
m1v1 + m2v2=0
m1= mass of log
m2 = mass of lumber jack
v1 = velocity of log
v2 = velocity of lumber jack
a) Velocity of first log
m/s
b) m1v1 + m2v2 = m3v3
Velocity of log
=
To solve this problem it is necessary to apply the concepts related to rate of thermal conduction
The letter Q represents the amount of heat transferred in a time t, k is the thermal conductivity constant for the material, A is the cross sectional area of the material transferring heat, , T is the difference in temperature between one side of the material and the other, and d is the thickness of the material.
The change made between glass and air would be determined by:
There are two layers of Glass and one layer of Air so the total temperature would be given as,
Finally the rate of heat flow through this windows is given as,
Therefore the correct answer is D. 180W.