A 1 kg block is projected upward along a 37° rough incline with speed 10 m/s. The coefficient of kinetic friction is 1/4. Take g = 10 m/s², sin37° = 3/5 and cos37° = 4/5. If the distance travelled before stopping is N/4 m, find N.
Physics · Work , Power and Energy · kinetic energy and work energy theorem
JEE Mains NEET JEE Advanced

Question

A 1 kg block is projected upward along a 37° rough incline with speed 10 m/s. The coefficient of kinetic friction is 1/4. Take g = 10 m/s², sin37° = 3/5 and cos37° = 4/5. If the distance travelled before stopping is N/4 m, find N.

Physics · Work , Power and Energy · kinetic energy and work energy theorem

G1 Physics · Accepted Answer

Down-slope gravity component = mg sin37° = 6 N. Friction = μmg cos37° = (1/4)(8) = 2 N. Total opposing force = 8 N. Initial K = ½(1)(10²) = 50 J. Therefore 50 = 8s ⇒ s = 25/4 m, so N = 25.