You can find the net force acting on a shopping cart if you know its acceleration using Newton's Second Law of Motion.

Here's the breakdown:

Newton's Second Law:

* F = m * a

Where:

* F is the net force (measured in Newtons, N)

* m is the mass of the shopping cart (measured in kilograms, kg)

* a is the acceleration of the shopping cart (measured in meters per second squared, m/s²)

To find the net force:

1. Identify the mass (m) of the shopping cart. You'll need this information.

2. Determine the acceleration (a) of the shopping cart. This could be given to you or you might need to calculate it based on other information (like initial and final velocities and time).

3. Plug the values of mass and acceleration into the equation: F = m * a

4. Calculate the result. The answer will be the net force acting on the shopping cart in Newtons.

Example:

Let's say a shopping cart with a mass of 15 kg accelerates at 2 m/s².

* F = (15 kg) * (2 m/s²)

* F = 30 N

Therefore, the net force acting on the shopping cart is 30 Newtons.