How much work is done against the gravitational force on a 3.0 kg object when it is carried from the ground floor to the roof of a building, a vertical climb of 240 m?
A
7.2 kJ
B
4.6 kJ
C
6.8 kJ
D
8.4 kJ
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
The work done against the gravitational force is calculated using the formula W = mgh, where m is the mass of the object, g is the acceleration due to gravity (approximately \(9.8 ms^2\) on Earth), and h is the height. Substituting the given values, we get W = 3.0 kg * \(9.8 m/s^2\) * 240 m = 7.2 kJ. Therefore, the correct answer is '7.2 kJ'.
Source: WAEC / JAMB / NECO Classroom Archive (Record #68116)