Final answer:
The 74 kg astronaut exerts a force of 725.54 newtons on the chair at rest on the launch pad, calculated using the product of the astronaut's mass and Earth's gravitational acceleration.
Step-by-step explanation:
The force that a 74 kg astronaut exerts on his chair while sitting at rest on the launch pad is calculated using the equation for weight (Weight = mass × gravity). The standard acceleration due to gravity on Earth is about 9.81 m/s². Therefore, the force can be calculated as follows:
F = m × g
F = 74 kg × 9.81 m/s²
F = 725.54 N
Thus, the astronaut exerts a force of 725.54 newtons on his chair while sitting at rest on the launch pad.