Question

The kinetic energy of a particle continuously increases with time. We can conclude that :

• A. the resultant force on the particle must be parallel to the velocity at all instants.
• B. the resultant force on the particle must be at an angle less than 90${}^o$ all the time.
• C. its height above the ground level must continuously decrease.
• D. the magnitude of its linear momentum is increasing continuously.

Answer 1

Answer: (B), (D)

the resultant force on the particle must be at an angle less than 90${}^o$ all the time.
the magnitude of its linear momentum is increasing continuously.

If the kinetic energy of a particle continuously increases with time, The resultant force on the particle must be at an angle less than ${90}^{\circ }$ all the time. Hence ,the magnitude of its linear momentum increases continuously.