Which instrument measures force in Newtons (N)?

• A. Spring Scale
• B. Anemometer
• C. Thermometer
• D. Ruler

Answer: (A)

A spring scale is used to measure force in Newtons. It works on Hooke’s law: as the force pulls on the spring, the spring stretches by an amount proportional to the force (F = kx). The device is calibrated so that this stretch is read directly as a force in Newtons, making it the right tool for gauging how hard something is pulling.

The other tools measure different things: an anemometer gauges wind speed, a thermometer measures temperature, and a ruler measures length. So for force in Newtons, the spring scale is the appropriate instrument.