iGCSE Physics (0625) 1.1 Physical quantities and measurement techniques-Exam Style Questions- New Syllabus
▶️ Answer/Explanation
Detailed solution:
A ruler is a primary instrument used to measure the physical dimension of length $l$.
While option A involves distance, it requires a synchronized timer to measure exactly what is covered in $1~s$.
Temperature (B) requires a thermometer, and time (C) requires a stopwatch or digital timer.
Volume $V$ for a regular object is derived from length measurements (e.g., $V = l \times w \times h$).
Since a ruler can measure the dimensions required to calculate the space an object occupies, it is the correct tool.
Therefore, the volume of the toy train is the most appropriate quantity listed that relies on ruler measurements.
▶️ Answer/Explanation
Detailed solution:
A vector quantity is defined as having both magnitude and direction. Acceleration is a vector because it is the rate of change of velocity, which includes direction. Force is also a vector as it is defined by its magnitude and the specific direction in which it acts, represented by $F = ma$. Conversely, density ($\rho = \frac{m}{V}$) and pressure ($p = \frac{F}{A}$) are scalar quantities because they only possess magnitude. Since Option A lists two quantities that both require direction to be fully described, it is the correct choice.
▶️ Answer/Explanation
Detailed solution:
First, calculate the total time elapsed: $2$ min $18$ s ($138$ s) minus $1$ min $30$ s ($90$ s) equals $48$ s.
Since the pendulum passes the marker $12$ more times from the same direction, it has completed $n = 12$ full oscillations.
The time period $T$ is defined as the total time $t$ divided by the number of oscillations $n$.
Using the formula $T = \frac{t}{n}$, we get $T = \frac{48\text{ s}}{12}$.
This results in a time period of $4.0$ s per oscillation.
Therefore, the correct period of oscillation is $4.0$ s, matching option A.