Final answer:
The force exerted by an 86.0 kg astronaut on his chair while at rest on the launch pad is the astronaut's weight, approximately 843.66 Newtons.
Step-by-step explanation:
The force that an 86.0 kg astronaut exerts on his chair while sitting at rest on the launch pad is equal to the astronaut's weight. This weight can be calculated using the force due to gravity on Earth, which is approximately 9.81 m/s². By multiplying the astronaut's mass by the acceleration due to gravity, we get the force (weight) exerted:
Force (weight) = mass × acceleration due to gravity
Force = 86.0 kg × 9.81 m/s²
Force = 843.66 N
Therefore, the astronaut exerts a force of approximately 843.66 Newtons on his chair.