Physics SEM2

 Q2 )

Explain the motion of an object in the following situation which suitable example A speed is constant and velocity is varying B acceleration of a body is constant but velocity is zero C speed is constant and acceleration is zero D force is applied but acceleration is zero

Solution

A) Speed is constant, and velocity is changing:

In this scenario, the object's speed remains the same, but the direction of its velocity is changing. This situation occurs when an object moves in a circular path at a constant speed. For example, consider a car driving in a circular track at a constant speed of 60 miles per hour. Although the car maintains the same speed, its velocity is constantly changing because it keeps changing direction as it moves along the circular path.

B) Acceleration of a body is constant, but velocity is zero:

In this case, the object is not moving (velocity is zero), but it experiences a constant acceleration. An example of this is an object in free fall. Imagine dropping a ball from a height. At the moment it is released, its velocity is zero, but it accelerates downward due to the force of gravity. During its descent, the ball's velocity remains zero, but its acceleration is constant (approximately 9.8 m/s² downward).

C) Speed is constant, and acceleration is zero:

When an object maintains a constant speed and its acceleration is zero, it means that there is no change in its velocity over time. An example could be a car traveling on a straight road at a constant speed of 50 miles per hour. As long as there are no external forces or changes in conditions, the car will continue to move at the same speed in a straight line without any change in its velocity.

D) Force is applied, but acceleration is zero:

In this scenario, a force is being applied to an object, but its acceleration is zero. This situation occurs when the applied force is balanced by an equal and opposite force, resulting in a state of equilibrium. A common example is a book resting on a table. The force of gravity pulls the book downward, but the table exerts an equal and opposite force, balancing the gravitational force. As a result, the book remains stationary, and its acceleration is zero.

It's important to note that velocity and acceleration are vector quantities, meaning they have both magnitude and direction. Speed, on the other hand, is a scalar quantity that only represents the magnitude of velocity.