Concept explainers
(a)
The magnitude of the combined
(a)
Answer to Problem 99P
The magnitude of the combined force of friction at
Explanation of Solution
Given:
On a
Formula used:
Magnitude of force of friction at
The diagram representing the situation is given below.
Write the equation of resultant along the incline in equilibrium position.
Here,
Substitute
Rearrange above equation.
Here,
Calculation:
Whenspeed of car is
Substitute
Whenspeed of car is
Substitute
Conclusion:
Thus, the magnitude of the combined force of friction at
(b)
The power delivered by the engine to drive the car on a level road at
(b)
Answer to Problem 99P
The power delivered by the engine to drive the car on a level road at
Explanation of Solution
Given:
On a
Formula used:
Power delivered by the engine to drive the car on a level road at
Power delivered by the engine to drive the car on a level road in order to overcome friction is calculated by the expression given below.
Write the expression for power delivered.
Here,
Calculation:
Substitute
Substitute
Conclusion:
Thus, the power delivered by the engine to drive the car on a level road at
(c)
The angle of the steepest incline up which can be maintained by car at steady speed of
(c)
Answer to Problem 99P
The angle of the steepest incline up which can be maintained by car at steady speed of
Explanation of Solution
Given:
On a
Formula used:
The diagram representing the situation is given below.
Write the equation of resultant along the incline in equilibrium position.
Here,
Substitute
Rearrange above equation.
Here,
Substitute
Rearrange above equation for
Calculation:
Substitute
Conclusion:
Thus, the angle of the steepest incline up which can be maintained by car at steady speed of
(d)
The total useful work in kilometers per liter when engine goes at
(d)
Answer to Problem 99P
The total useful work in kilometers per liter when engine goes at
Explanation of Solution
Given:
The magnitude of the combined force of friction at
Formula used:
Write the expression for work done by engine.
Here,
From the condition of equivalence:
Here,
Rearrange above equation.
Calculation:
Substitute
Conclusion:
Thus, the total useful work in kilometers per liter when engine goes at
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Chapter 7 Solutions
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