Question

The potential energy $\phi$, in joule, of a particle of mass 1 kg, moving in the x-y plane, obeys the law $\phi$= 3x + 4y, where (x, y) are the coordinates of the particle in metres. If the particle is at rest at (6,4) at time t = 0, then

• A. The particle has constant acceleration.
• B. The work done by the external forces, the position of rest of the particle and the instant of the particle crossing the x-axis is 25 J.
• C. The speed of the particle when it crosses the y-axis is 10$m{s}^{-1}$.
• D. The coordinates of the particle at time t = 4 s are (-18, -28).

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A The particle has constant acceleration.
B The work done by the external forces, the position of rest of the particle and the instant of the particle crossing the x-axis is 25 J.
C The speed of the particle when it crosses the y-axis is 10$m{s}^{-1}$.
D The coordinates of the particle at time t = 4 s are (-18, -28).