Question

1. a 2 kg box is held up by a rope. what tension must the rope have to keep the box at rest?

Explanation:

Step1: Identify the forces

The box is at rest, so the net force is zero. The forces acting on the box are gravity (weight) downward and tension upward.

Step2: Calculate the weight

The weight \( W \) of an object is given by \( W = mg \), where \( m = 2\space kg \) and \( g = 9.8\space m/s^2 \). So \( W = 2\times9.8 = 19.6\space N \).

Step3: Relate tension and weight

Since the box is in equilibrium, tension \( T \) equals weight \( W \). So \( T = 19.6\space N \).

Answer:

The tension in the rope must be \( 19.6\space N \) (or approximately \( 20\space N \) if using \( g = 10\space m/s^2 \)).