Question

1. an object of mass 5.0 kg is lifted vertically upward by 2.0 m. assuming the acceleration due to gravity is 9.8 m/s², how much work is done against gravity?

a. 10 j
b. 20 j
c. 49 j
d. 98 j

Explanation:

Step1: Calculate the force due to gravity

The force due to gravity \(F = mg\), where \(m = 5.0\space kg\) and \(g=9.8\space m/s^{2}\).
\(F=5.0\times9.8 = 49\space N\)

Step2: Calculate the work done

The work done \(W = F\times d\), where \(d = 2.0\space m\) and \(F = 49\space N\) (from Step1).
\(W=49\times2.0=98\space J\)

Answer:

D. \(98\space J\)