Question

If a particle of mass $m$ is projected at an angle $\alpha$ with the horizontal, then:

• A. the angular momentum remains constant
• B. the linear momentum of particle remains constant
• C. total mechanical energy remains constant in the absence of air resistance
• D. all the above

Answer 1

Answer: (C)

Since, torque due to weight of particle about point of projection is not zero so, angular momentum of system about the point of projection does not remains constant. But the particle moves under conservative force (weight of the particle). So, mechanical energy of system remains constant, hence [c] is correct.