Three forces act on a particle so that it remains at rest

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

Three forces act on a particle so that it remains at rest. The first force is

10\,\text{N}

along the positive

x

-axis. The second force is

20\,\text{N}

directed

120^{\circ}

anticlockwise from the positive

x

-axis. What is the magnitude and direction of the third force? (a)

10\,\text N

along the negative

x

–axis (b)

20\,\text N

along the negative

y

–axis (c)

17.3\,\text N

along the negative

y

–axis (d)

17.3\,\text N

along the positive

y

–axis