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: Find weight of the object

The weight $F$ is $F = m \times g$, where $m=5.0\ \text{kg}$ and $g=9.8\ \text{m/s}^2$.
$F = 5.0\ \text{kg} \times 9.8\ \text{m/s}^2 = 49\ \text{N}$

Step2: Calculate work against gravity

Work $W$ is $W = F \times d$, where $d=2.0\ \text{m}$.
$W = 49\ \text{N} \times 2.0\ \text{m} = 98\ \text{J}$

Answer:

D. 98 J