Question

11 formula 1 point
a 6 kg box sits on a scale. a student presses down on the box with some amount of applied force. the scale measures a force of 110 newtons. calculate the force applied by the student in the downward direction. (typically we write applied forces as f_a with the a as a subscript. an applied force is typically just a push or a pull from a person)
answer

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Explanation:

Step1: Calculate weight of box

Weight \( W = mg \), \( m = 6\,\text{kg} \), \( g = 9.8\,\text{m/s}^2 \), so \( W = 6\times9.8 = 58.8\,\text{N} \).

Step2: Relate scale force to weight and applied force

Scale force \( F_{\text{scale}} = W + F_A \), so \( F_A = F_{\text{scale}} - W \).
Substitute \( F_{\text{scale}} = 110\,\text{N} \), \( W = 58.8\,\text{N} \), \( F_A = 110 - 58.8 = 51.2\,\text{N} \).

Answer:

\( 51.2\,\text{Newtons} \) (or using \( g = 10\,\text{m/s}^2 \), \( F_A = 110 - 60 = 50\,\text{N} \), depending on \( g \) approximation)