Answer: B.) HYDROPLANE
Explanation: The term hydroplane can be used to refer to a condition which usually occur during a downpour or on surfaces covered by water. It occurs when water forms a barrier or comes in between the frictional grip which occurs between the road surface and the car tyres. The contact between the car tyres and the road surface is supposed to give adequate frictional support which prevents the car from skidding or skidding uncontrollably on the road surface. However, when water comes invetween the surface, traction is lost and skidding results due to very low Coefficient of friction between the road and Tyre which was supposed to provide a firm grip between the tyres and the road surface.
Answer:
D)378kJ
Explanation:
Applying,
E = F×d................ Equation 1
Where E = Energy expanded by the car, F = Wind resistance, d = distance
From the question,
F = 0.42v²............ Equation 2
Susbtitute equation 2 into equation 1
E = 0.42v²d.............. Equation 3
Given: v = 30 m/s, d = 1 km = 1000 m
Substitute these values into equation 3
E = 0.42(30²)(1000)
E = 378000
E = 378 kJ
Hence the right option is D)378kJ
Complete Question
A ball having mass 2 kg is connected by a string of length 2 m to a pivot point and held in place in a vertical position. A constant wind force of magnitude 13.2 N blows from left to right. Pivot Pivot F F (a) (b) H m m L L If the mass is released from the vertical position, what maximum height above its initial position will it attain? Assume that the string does not break in the process. The acceleration of gravity is 9.8 m/s 2 . Answer in units of m.What will be the equilibrium height of the mass?
Answer:


Explanation:
From the question we are told that
Mass of ball 
Length of string 
Wind force 
Generally the equation for
is mathematically given as




Max angle =
Generally the equation for max Height
is mathematically given as



Generally the equation for Equilibrium Height
is mathematically given as



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