Physics chapter 1

Physical Quantity

A quantity that can be measured.

Precision

The smallest unit an instrument can measure.

Parallax error

Occurs when your eyes’ line of sight is not perpendicular to the ruler.

Zero error

Introduced when using a metre rule with its zero end worn out.

Linearly

In a straight line.

Scalar quantity

A physical quantity that has magnitude only.

Vector quantity

A physical quantity that has both magnitude and direction.

What is the difference between Speed and Velocity?

Speed is a scalar quantity (magnitude only), while Velocity is a vector quantity (magnitude and direction).

What is the formula for the volume of a rectangular block?

Volume = l × b × h.

What is the formula for the volume of a cylinder?

Volume = π r² h.

What is the formula for the volume of a sphere?

Volume = 4/3π(d/2)³.

What is meant by 'one oscillation' in the context of time measurement?

Each complete to-and-fro motion.

What is the period of a simple pendulum?

The time taken for one complete oscillation.

How do you add scalars?

By adding their magnitudes only.

What must we find when adding vectors?

A single vector known as the resultant vector, equivalent to the individual vectors combined in magnitude and direction.

What is the formula for the resultant vector?

Resultant vector = √(Rv² + RH²).

How do you find the angle of the resultant vector?

θ = tan−1(Rv/RH).