A vehicle of mass m is moving on a rough horizontal road with momentum p. If the coefficient of friction between the tyres and the road be μ, then the stopping distance is:
A
μmgp2
B
2μmgp2
C
μm2gp2
D
2μm2gp2
Step-by-Step Solution
Kinetic Energy and Momentum: The kinetic energy (K) of a body can be expressed in terms of its momentum (p) and mass (m) as:
K=2mp2
[Source 57, 78].
Work Done by Friction: When the vehicle stops, the work done by the frictional force (f) opposes the motion and dissipates the kinetic energy. The frictional force on a horizontal road is f=μN=μmg.
The work done over stopping distance s is W=f⋅s=μmgs [Source 64, 80].
Work-Energy Theorem: According to the theorem, the work done by the retarding force equals the change in kinetic energy (magnitude wise):
μmgs=K=2mp2
Solving for Stopping Distance (s):s=2m(μmg)p2=2μm2gp2
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