Question
Question: The radius of front wheel of arrangement shown in Fig. is a and that of rear wheel is b. If a dust p...
The radius of front wheel of arrangement shown in Fig. is a and that of rear wheel is b. If a dust particle driven from the highest point of rear wheel alights on the highest point of front wheel, the velocity of arrangement is

[g(c+a−b)(b−a)(c−a+b)]1/2
g4(b−a)(c+a−b)
[g4(b−a)(c+a−b)(c−a+b)]1/2
[g4(c−a)(c−a+b)]1/2
[g4(b−a)(c+a−b)(c−a+b)]1/2
Solution
Let t be time of flight of the particle from P to Q. Since e is the distance between the centres of the two wheels, the horizontal distance between the wheels.
ch = c2−(b−a)2
If v is the velocity of the carriage,
then ch = vt (horizontal range)
or vt = c2−(b−a)2 or t = v1c2−(b−a)2
In this time, the particle has covered the vertical distance = 2(b - a).
∴ 2(b - a) = 21gt2
or2(b−a)=21gv2[c2−(b−a)2]or v2 = 4g(b−a)c2−(b−a)2
or v = [g4(b−a)(c+a−b)(c−a+b)]1/2