Concept explainers
(a)
The value the drag constant c.
Answer to Problem 84QAP
The value the drag constant c is
Explanation of Solution
Given:
Terminal velocity of the raindrop
Diameter of the drop
Density of water
Equation for the drag force
Formula used:
If the drop moves with terminal velocity, then the drag force acting upwards is equal to the drop's weight w.
If m is the mass of the drop, V its volume and g the acceleration of free fall, then,
And,
Since the volume is given by,
This follows that,
Since
Write an expression for c.
Calculation:
Determine the radius of the drop and express it in m.
Substitute the given values in the expression and calculate the value of c.
Conclusion:
The value the drag constant c is
(b)
The value of the terminal velocity of a drop of diameter 8.00 mm under the same conditions.
Answer to Problem 84QAP
The value of the terminal velocity of a drop of diameter 8.00 mm
is 24.04 m/s.
Explanation of Solution
Given:
The terminal velocity of the drop of diameter 4.00 mm
Diameter of the drop 1
Diameter of the drop 2
Formula used:
From the equation
it can be seen that, since
Therefore,
Therefore,
Calculation:
The diameter of the drop 2 is 8.00 mm, which is 2 times the diameter of drop 1.
Therefore,
The equation (2) reduces to,
Substitute the value of the terminal velocity of drop1 and calculate the value of the terminal velocity of drop 2.
Conclusion:
The value of the terminal velocity of a drop of diameter 8.00 mm
is 24.04 m/s.
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Chapter 5 Solutions
COLLEGE PHYSICS
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- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning