Test: Motion In One Dimension - Class 9 MCQ

For an object moving in a circular path, the distance traveled is equal to the circumference of the circle, while the displacement is zero as the object returns to its starting point. This highlights the importance of understanding how motion can be characterized differently depending on the context.

The formula for acceleration is a = (v - u)/t, where 'v' is the final velocity, 'u' is the initial velocity, and 't' is the time taken for the change. This formula allows us to quantify how quickly an object speeds up or slows down, which is essential in dynamics.

The acceleration due to gravity near the Earth's surface is approximately 9.8 m/s². This value is crucial for calculations involving freely falling objects and helps understand the effects of gravity on motion, including projectiles and other falling bodies.

Negative acceleration, or retardation, occurs when an object is slowing down. In physics, this concept is essential for understanding how forces act on moving objects, particularly in scenarios involving brakes or friction.

Scalar quantities are defined by having only magnitude and require a unit and numerical value to fully express them, while vector quantities have both magnitude and direction, necessitating that they be represented with a direction. Examples of scalar quantities include distance and speed, while examples of vector quantities include displacement and velocity. This distinction is crucial in physics, as it influences how these quantities are manipulated in calculations.

Instantaneous speed refers to the speed of an object at a specific moment in time. This measurement can be obtained using speedometers in vehicles and is crucial for understanding how speed varies in real-time.

Speed measures how fast an object is moving, but it does not take direction into account, making it a scalar quantity. Understanding this distinction is essential for analyzing motion accurately, especially in physics problems.

Uniform velocity is characterized by covering equal displacements in equal time intervals in a consistent direction. This means the object is moving at a constant speed in a straight line, making it easier to predict its future position.

One-dimensional motion occurs along a straight line and is characterized by no lateral movement. Common examples include a car driving on a straight road or an object falling vertically. This simplification helps in analyzing motion using linear equations and graphs.

A curved line on a velocity-time graph indicates variable acceleration, meaning the object's acceleration is changing over time. This reflects real-world scenarios where forces may vary, affecting how speed changes.

Displacement can indeed be zero even when distance is not, such as when an object returns to its starting point after moving. This is a critical concept in understanding how displacement differs from distance, as displacement includes direction and can be positive or negative based on the starting and ending positions.

The slope of a velocity-time graph represents acceleration. A steeper slope indicates a greater acceleration, while a flat line indicates constant velocity. This graphical representation is vital for visualizing how an object's speed changes over time.

When an object is thrown upwards, it experiences negative acceleration, or retardation, due to the force of gravity acting against its motion. This acceleration reduces the object's upward speed until it reaches its maximum height before falling back down.

The area under the curve in a velocity-time graph represents the distance traveled by the object. This relationship is crucial for solving problems related to motion and understanding how an object's speed contributes to the total distance over time.

Average speed is calculated by dividing the total distance traveled by the total time taken. This measure provides a way to understand how quickly an object is moving over a specific period, regardless of any variations in speed during that time.