A car is moving on a plane inclined at 30 ° to the horizontal with an acceleration of 10   m   s - 2 parallel to the plane upward. A bob is suspended by a string from the roof of the car. The angle in degrees which the string makes with the vertical is (Take g = 10   m   s - 2 )

Step-by-step solution

First, make the free body diagram, of an inclined plane with acceleration in an inclined plane moving in an upward direction. With respect to the car, the F.B.D. is as follows at equilibrium, T is equal and opposite to the resultant of a 1 ​ and a 2 ​ As a 1 + a 2 ​ makes 30 ° with vertical; T and, the string is also making 30 ° with vertical.