Important physics test! consider the free-body diagram. based on the net forces illustrated here, what can you say about the acceleration of the object? the object is accelerating in an upward direction. the object is moving at a constant speed. the acceleration equals 0. the object is accelerating down.

As per given FBD we can see that there are four forces acting on it

now if we consider horizontal forces we can see that

so there is no force along horizontal direction

along Y direction we can see there are two forces one force is 600 N upwards while other is 720 N downwards

So net force on the object will be given as

now overall due to all four forces we can see there is only 120 N net force on the object which is inclined downwards

So here this object will accelerated along the direction of net force

so correct answer will be

The object is accelerating down.

no. dot product   =0 when vecs at right angles