A body of mass 2 ~kg slides down with an acceleration of 3 ~m / s ^2 on a rough inclined plane having a slope of 30^ . The external force required to take the same body up the plane with the same acceleration will be: ( g =10 ~m / s ^2 )

Step-by-step solution

Equation of motion when the mass slides down aligned &M g -f=M a & 10-f=6 & (M=2 ~kg , a=3 ~m / s ^2, =30^ given ) & f=4 ~N aligned Equation of motion when the block is pushed up Let the external force required to take the block up the plane with same acceleration be F aligned &F-M g -f=M a & F-10-4=6 &F=20 ~N aligned