Physics - Term 2 - Week 4

Kinematics is the branch of physics that deals with the motion of objects without considering the forces that cause the motion. The primary quantities in kinematics include displacement, which is the change in position of an object, and distance, which is the total path length traveled. Velocity is defined as the rate of change of displacement, while acceleration is the rate of change of velocity. Understanding these concepts is crucial for analyzing motion in one dimension.

Consider a car that travels 100 meters east and then 50 meters west. To find the displacement, we take the final position minus the initial position. The displacement is 100 m (east) - 50 m (west) = 50 m (east). This example illustrates how displacement can differ from the total distance traveled.

A cyclist travels 200 meters in 10 seconds. To find the average velocity, we use the formula: velocity = displacement/time. Here, the displacement is 200 m and the time is 10 s. Thus, the average velocity is 200 m / 10 s = 20 m/s. Students should practice calculating average velocity for different scenarios, ensuring they understand the relationship between distance and time.

Students will solve a set of problems where they calculate acceleration. For example, if a car increases its velocity from 0 m/s to 25 m/s in 5 seconds, the acceleration can be calculated using the formula: acceleration = (final velocity - initial velocity) / time. Students should work through various problems to reinforce their understanding of how to apply this formula in different contexts.

• The total distance traveled by an object.
• The shortest distance from the initial to the final position.
• The speed of an object in a given direction.
• The rate of change of velocity.

Answer: The shortest distance from the initial to the final position.

Displacement is defined as the shortest straight-line distance from the starting point to the endpoint, taking direction into account.

• Distance
• Speed
• Velocity
• Time

Answer: Velocity

Velocity is a vector quantity as it has both magnitude and direction, while distance and speed are scalar quantities.

Answer: 8 m/s

Average speed is calculated as total distance divided by total time. Here, 400 m / 50 s = 8 m/s.

• It is increasing.
• It is decreasing.
• It is zero.
• It is constant.

Answer: It is zero.

Constant velocity means there is no change in speed or direction, which indicates that acceleration is zero.

Answer: a = (v_f - v_i) / t

Acceleration is calculated using the change in velocity (final velocity minus initial velocity) divided by the time taken.

• 3 m/s²
• 6 m/s²
• 0.3 m/s²
• 30 m/s²

Answer: 3 m/s²

Acceleration is calculated as (30 m/s - 0 m/s) / 10 s = 3 m/s².

• A straight horizontal line.