2023 - JAMB Physics Past Questions and Answers - page 6

The work done against the gravitational force is indeed calculated using the formula $W=mgh$, where $m$ is the mass of the object, $g$ is the acceleration due to gravity (approximately $9.8m/s^2$ on Earth), and $h$ is the height.

Substituting the given values:

$$W=3.0\text{kg}\times 9.8{\text{m/s}}^2\times 240\text{m}$$

$$W=7.2\text{kJ}$$

Therefore, the correct answer is 7.2 kJ

Users' Answers & Comments

The type of incandescent light source among the options is Tungsten filament lamp.

Incandescent light sources produce light by heating a filament until it becomes hot and glows. Tungsten filament lamps are a common example of incandescent light sources, where the filament is made of tungsten.

Users' Answers & Comments

The electrolyte used in the Nickel-Iron (NiFe) accumulator is Potassium hydroxide solution.

Nickel-Iron accumulators, also known as Edison batteries, use potassium hydroxide (KOH) solution as the electrolyte.

Users' Answers & Comments

Given:
- Amplitude ($A$) = 0.8 m
- Frequency ($f$) = 16 Hz
- Wave speed ($v$) = 20 $m/s$

First, calculate the wavelength ($\lambda$) using the formula $v=f\lambda$:

$$\lambda =\frac{v}{f}=\frac{20\text{m/s}}{16\text{Hz}}=1.25\text{m}$$

Then, calculate the wave number ($k$) using the formula $k=\frac{2\pi }{\lambda }$:

$$k=\frac{2\pi }{1.25}\approx 5{\text{m}}^{-1}$$

Therefore, the correct answer is 5 (to 1 significant figure)

Users' Answers & Comments