Velocity is an object or somethings speed in a given direction and since this object has been described as 'stationary' so its velocity would be 0 ^^;
The answer is reflex actions.
A reflex action is an involuntary and rapid reaction to a stimulus. So, when a receptor detects a stimulus, the information is sent to relay neuron through a sensory neurone. Relay neuron sends information to the effector through a motor neurone and effector produces a response.
