SCIENCE 7. Q3. Module 2 - Speed, Velocity and Acceleration

This paragraph introduces the cheetah (Acinonyx jubatus) as the fastest land animal, capable of reaching speeds between 112 to 120 kilometers per hour. It highlights the cheetah's ability to cover distances of 460 meters to 1500 feet in just three seconds. The paragraph also presents three questions related to the cheetah's speed, the distance it covers in three seconds, and its predatory advantages. The discussion transitions into a science lesson about motion, emphasizing the importance of understanding speed, velocity, and acceleration in describing an object's motion.

The paragraph delves into the concepts of speed and velocity, distinguishing between the two. Speed is defined as a scalar quantity that measures how fast an object is moving with respect to the distance traveled and time, commonly denoted by the symbol 'v'. Velocity, on the other hand, is a vector quantity that considers both speed and direction, symbolized by 'u'. The text provides a formula for calculating speed (distance over time) and explains how changes in magnitude and direction can result in acceleration. It also presents a short quiz to test the understanding of speed versus velocity.

This section focuses on practical examples of calculating speed and velocity. It explains how to determine the speed of a car moving at a uniform rate, using the formula speed = distance/time. The example given involves a car traveling 30 miles north in 0.5 hours, resulting in a speed of 60 miles per hour. The paragraph further clarifies the difference between speed and velocity, emphasizing that velocity includes direction. It introduces the concept of acceleration, denoted by 'a', and explains it as the change in velocity over time, with the unit being meters per second squared.

The paragraph discusses acceleration, which occurs when there is a change in velocity or direction, or both. It explains how acceleration is calculated using the formula a = (final velocity - initial velocity) / time. The unit of acceleration is meter per second squared, with the standard acceleration due to gravity being 9.8 m/s². The text also provides a table to illustrate how different positions correspond to varying states of motion, such as stationary or slowing down. The paragraph concludes with a recap of key concepts learned about speed, velocity, and acceleration.

In the concluding paragraph, the science teacher summarizes the lesson's main points, emphasizing the importance of understanding how speed and velocity describe an object's motion and direction. It reiterates that a stationary object has a speed of zero, and that constant motion involves equal distances covered in equal time intervals. The concept of acceleration is also highlighted as a change in speed or direction, or both. The teacher encourages students to stay tuned for the next topic on motions and reminds viewers to subscribe, like, and turn on notifications for more science updates.