Understanding the Concepts

* Force (F): A push or pull that can cause a change in an object's motion. Measured in Newtons (N).

* Mass (m): The amount of matter in an object. Measured in kilograms (kg).

* Acceleration (a): The rate at which an object's velocity changes. Measured in meters per second squared (m/s²).

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

Calculation

1. Identify the knowns:

* Mass (m) = 70 kg

* Acceleration due to gravity (a) = 9.8 m/s²

2. Apply Newton's Second Law:

* Force (F) = mass (m) * acceleration (a)

* F = 70 kg * 9.8 m/s²

3. Calculate the force:

* F = 686 N

Answer

The force acting on the skydiver is 686 Newtons (N).

Units Explanation

* Newtons (N): The standard unit of force. 1 Newton is defined as the force required to accelerate a 1 kg mass at 1 m/s².

* Kilograms (kg): The standard unit of mass.

* Meters per second squared (m/s²): The standard unit of acceleration.

Important Note: This calculation assumes that the only force acting on the skydiver is gravity. In reality, air resistance (drag) would also play a significant role, especially as the skydiver reaches terminal velocity.