What is a correct unit for the area under a force-time graph? A N m B kg m s⁻¹ C kg m s² D N s⁻¹ - AQA - A-Level Physics - Question 7 - 2018 - Paper 1

To determine the correct unit for the area under a force-time graph, we must understand that the area represents the impulse experienced by an object, which is the change in momentum.

Impulse can be computed as the product of force and time, which is given by the formula:

$ext{Impulse} = ext{Force} imes ext{Time}$

The unit of force is newtons (N), and the unit of time is seconds (s). Therefore, we can express the impulse in units as follows:

$ext{Unit of Impulse} = N imes s$

This means that the correct unit for the area under a force-time graph is newton-seconds (N s).

Thus, the answer is D: N s⁻¹.