Motion – Acceleration (Part-4)

• Acceleration is defined as the rate of which the velocity of an object changes.
• Acceleration = Change in Velocity/Time Taken (For uniform velocity only)
• Change in velocity may be due to change in speed or due to change in the direction of motion.
• Acceleration has both magnitude as well as direction, hence it is a vector quantity.
• Acceleration is positive when it is in the direction of velocity.
• Acceleration is negative when it is in the opposite direction of velocity.
• Negative acceleration is also known as Retardation or deceleration.
• If an object is slowing down then its acceleration is in an opposite direction to its motion, i.e. deceleration.
• Acceleration is negative when Initial Velocity > Final Velocity.
• Acceleration is 0 when Initial Velocity = Final Velocity
• Acceleration is positive when Final Velocity > Initial Velocity.

SI Unit of Accceleration

• SI Unit of Velocity ⇒ m/s
• SI Unit of Time ⇒ s
• Therefore, SI Unit of Acceleration ⇒ (m/s)/s = m/s2