Solution Found!
(a) Calculate the retarding force due to the viscosity of
Chapter 12, Problem 29(choose chapter or problem)
Problem 29PE
(a) Calculate the retarding force due to the viscosity of the air layer between a cart and a level air track given the following information—air temperature is 20º C , the cart is moving at 0.400 m/s, its surface area is 2.50×10−2 m 2 , and the thickness of the air layer is 6.00×10−5 m . (b) What is the ratio of this force to the weight of the 0.300-kg cart?
Questions & Answers
QUESTION:
Problem 29PE
(a) Calculate the retarding force due to the viscosity of the air layer between a cart and a level air track given the following information—air temperature is 20º C , the cart is moving at 0.400 m/s, its surface area is 2.50×10−2 m 2 , and the thickness of the air layer is 6.00×10−5 m . (b) What is the ratio of this force to the weight of the 0.300-kg cart?
ANSWER:
a.)
Step 1 of 2
The retarding force (F) due to the viscosity of the air layer is given by the expression,
where, viscosity of the air at 20 oC in Pas
v = velocity of the cart in m/s
A = Surface area in m2
L = thickness of the air layer in m
Substituting 15.1110-6 Pas for , 0.400 m/s for v, 2.5010-2 m2 for A and 610-5 m for L
=
=0.00252 N
Therefore, the retarding force due to the viscosity of the air layer between a cart and a level air is 0.00252 N
b.)