Question

Two blocks A and B kept on smooth horizontal surface are acted upon by few forces as shown. Initially block A is moving towards right with constant speed and block B is at rest. After the application of forces on both as shown. What will happen ?

• A. A comes to rest and B starts moving towards right
• B. A keeps moving towards right and B remains at rest
• C. A moves towards left and B towards right
• D. Both A and B moves towards right

Answer 1

The correct option is D Both A and B moves towards right

Forces on Block A:

Initially, Block A is moving with constant speed.
12 N force is applied toward right direction,
5 N and 7N forces are toward left direction,
Net force toward left direction= 5N+7N= 12 N
Net force on Block A = 12 N - 12 N = 0
Thus forces are balanced, So block A will keep moving towards right with constant speed Forces on Block B:

Initially, Block B is at rest.
10 N and 12 N and 2 N forces are applied toward the right direction. Net force toward right direction = 10N + 12 N +2N = 24 N
Thus force on Block B is unbalanced, So block B will move toward the right direction.
So correct option is option D