Let's break down this problem. It seems there's a slight misunderstanding: acceleration is measured in meters per second squared (m/s²), not just meters (m).

Here's how to calculate the force the astronaut exerts on the chair:

1. Understand the Concepts:

* Newton's Second Law of Motion: This states that the force (F) acting on an object is equal to its mass (m) multiplied by its acceleration (a): F = ma.

* Force and Reaction: For every action, there is an equal and opposite reaction. When the astronaut pushes down on the chair, the chair pushes back on the astronaut with the same force.

2. Calculate the Force:

* Mass (m): 70 kg

* Acceleration (a): 19 m/s²

* Force (F): F = ma = (70 kg) * (19 m/s²) = 1330 N (Newtons)

Therefore, the astronaut exerts a force of 1330 Newtons on the chair.