The potential energy

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

\phi

, in joules, of a particle of mass

1\,\mathrm{kg}

moving in the

x

y

plane obeys

\phi=3x+4y

, where

x

and

y

are in metres. If the particle is at rest at

(6\,\mathrm{m},8\,\mathrm{m})

at time

0

, then the work done by the conservative force from the initial position to the instant when it crosses the

x

-axis is (1)

25\,\mathrm{J}

(2)

-25\,\mathrm{J}

(3)

50\,\mathrm{J}

(4)

-50\,\mathrm{J}