Physics
Chapter No 03
Kinematics
Question No 10
What is deceleration or retardation ?
Answer :
Deceleration or Retardation: when an object speed is slowing down we can say that it is decelerating . This is known as deceleration are retardation.
Explaination: Deceleration or retardation refers to the decrease in speed or velocity of an object over time. It is the opposite of acceleration, which refers to an increase in speed or velocity. Both deceleration and acceleration are components of the broader concept of kinematics, which deals with the motion of objects without considering the forces that cause that motion.
Question No 11
What is positive and negative acceleration?
Answer
Positive acceleration: if the speed of a body increases to the positive axis the acceleration is said to be positive.
Explaination: Positive acceleration occurs when an object's speed or velocity increases with time. It can occur when an object is moving in the same direction as the applied force.
For example: when a car accelerates from rest to a higher speed, the car experiences positive acceleration. Another example is when a person throws a ball upwards and it accelerates upwards due to the force applied. The velocity and acceleration vectors have the same direction in positive acceleration.
Negative acceleration: if the speed of a body decreases toward the negative axis then the acceleration is said to be negative.
Explaination: Negative acceleration, also known as deceleration, occurs when an object's speed or velocity decreases with time. It can occur when an object is moving in the opposite direction to the applied force. When a car applies its brakes to slow down, it experiences negative acceleration. Similarly, when you throw a ball upwards and it slows down before coming to a stop and falling back down, it experiences negative acceleration. In negative acceleration, the velocity and acceleration vectors have opposite directions.
Acceleration can be positive and negative: It is important to note that acceleration can be positive or negative regardless of the direction of the object's motion.
For example: if a car is moving forward and then starts slowing down, it experiences negative acceleration, even though its motion is still in the positive direction.
Acceleration, whether positive or negative, is typically expressed in meters per second squared (m/s*2) in the metric system. It represents how much the velocity of an object changes per unit of time.
Importance: Understanding acceleration and deceleration is crucial in various fields, such as physics, engineering, and transportation. It helps us analyze and predict the motion of objects, design vehicles with efficient braking systems, and ensure safety in various moving systems.
