A block is placed at the bottom of an inclined plane and projected upwards with some initial speed. It slides up the incline, stops after time t1, and slides back in a further time t2. The angle of inclination of the plane with the horizontal is θ and the coefficient of friction is μ.
(a) t1 > t2
(b) t1 < t2
(c) The retardation of the block while moving up is g(sin θ + μcos θ).
(d) The acceleration of the block while moving down is g(sin θ - μcos θ).
