Concepts Of Physics MCQ Edition [Volume 1]PhysicsCircular Motion
A block of mass m travels in a horizontal circle against the wall of a cylindrical room of radius R . The floor of the room is smooth, while the friction coefficient between the wall and the block is . The block is imparted an initial speed v₀ . Determine the tangential acceleration of the block as a function of the speed v .
Options
- A- g
- B- v₀^2 R
- C- v^2 R
- D- v^2 R
Correct answer
D. - v^2 R
Step-by-step solution
The normal force exerted by the cylindrical wall provides the necessary centripetal force for the block to move in a horizontal circle of radius R . N = mv^2 R The kinetic friction force from the wall acts tangentially, opposite to the direction of motion. f = N = mv^2 R By Newton's second law, the tangential acceleration a_t is given by: m a_t = -f m a_t = - m v^2 R a_t = - v^2 R