The air resistance to a car at 20 kmph is R. The air resistance at 40 kmph will be
A. R
B. 2R
C. 4R
D. 4R2
Answer: Option C
Solution (By Examveda Team)
R = K × A × V2 when vehicle speed is about 20 km/hrWhere K = Co-efficient of air resistance
A = Projected area of vehicle
V = Vehicle speed in km/hr
When vehicle speed is about 40 km/hr, speed is doubled so we can write V = 2V
Therefore, R = K × A × (2V)2
R = K × A × 4V2
R = 4K × A × V2
R = 4R
This Question Belongs to Mechanical Engineering >> Automobile Engineering
Why we take v2 as vehicle speed why not v in place of v2