Physics - Term 1 - Week 6

Kinematics is the branch of physics that describes the motion of objects without considering the forces that cause the motion. Displacement is a vector quantity that refers to the change in position of an object. Velocity, also a vector, is the rate of change of displacement with respect to time. Acceleration is the rate of change of velocity with respect to time. Understanding these concepts is crucial for analyzing motion.

Consider a car that travels 100 meters to the east in 5 seconds. To find the average velocity, we use the formula: average velocity = total displacement / total time. Here, the total displacement is 100 meters and the total time is 5 seconds. Thus, average velocity = 100 m / 5 s = 20 m/s to the east.

A cyclist increases their speed from 10 m/s to 25 m/s in 5 seconds. To find the acceleration, we use the formula: acceleration = (final velocity - initial velocity) / time. Substituting the values, we have acceleration = (25 m/s - 10 m/s) / 5 s = 3 m/s². Students should practice similar problems to reinforce this concept.

Students will solve a set of problems where they will apply the kinematic equations to find unknowns such as final velocity, time, or displacement. For instance, if an object starts from rest and accelerates at 2 m/s² for 10 seconds, what is its final velocity? Students should use the equation: final velocity = initial velocity + (acceleration × time).

• The total distance traveled
• The change in position of an object
• The speed of an object
• The time taken to travel a distance

Answer: The change in position of an object

Displacement is defined as the change in position of an object, taking into account the direction.

• Speed
• Distance
• Velocity
• Time

Answer: Velocity

Velocity is a vector quantity as it has both magnitude and direction, unlike speed which is scalar.

Answer: 15 m/s

Average velocity is calculated as total displacement divided by total time: 150 m / 10 s = 15 m/s.

• Acceleration = (final velocity - initial velocity) / time
• Acceleration = (initial velocity - final velocity) / time
• Acceleration = distance / time
• Acceleration = velocity × time

Answer: Acceleration = (final velocity - initial velocity) / time

This formula defines acceleration as the change in velocity over time.

Answer: 5 m/s²

Using the formula: acceleration = (20 m/s - 5 m/s) / 3 s = 5 m/s².

• d = vt + 0.5at²
• d = vt - 0.5at²
• d = v + at
• d = v - at

Answer: d = vt + 0.5at²

This equation describes the displacement of an object under constant acceleration.

Answer: 50 m/s north