The coefficient of static friction between the bodies A and B is 0.30. Determine minimum stopping distance that the body A can have from a speed of 70 km/h with constant deceleration if the body B is not to slip forward

Options

A. 3 m
B. 30.3 m
C. 70 km
D. 63 m

Answer

D

Explanation

The maximum deceleration is `a=mug = 3 m//s^(2)`
`therefore " "v^(2)=u^(2)-2as`
`0 =v_(0)^(2)-2mugs_("min")`
`therefore " "s_("min")=(v_(0)^(2))/(2mug)=((70xx(5)/(18)))/(6)=63 m`