(a) A car starts moving (at point A) on a horizontal circular track and moves in anticlockwise sense. The speed of the car is made to increase uniformly. The car slips just after point D. The figure shows the friction force (f) acting on the car at points A, B, C and D. The length of the arrow indicates the magnitude of the friction and it is given that `angleD gt angleB gt angleC`. At which point (A, B, C or D) the friction forces represented is certainly wrong ?
(b) A particle is moving along an expanding spiral (shown in fig) such that the normal force on the particle [i.e., component of force perpendicular to the path of the particle] remains constant in magnitude. The possible direction of acceleration`(veca)`of the particle has been shown at three points A, B and C on its path. At which of these points the direction of acceleration has been represented correctly.
(c) A particle is moving in XY plane with a velocity . `vecv = 4hati + 2thatj ms^(-1)` . Calculate its rate of change of speed and normal acceleration at t = 2 s.
