Understanding the Concepts
* Force of Gravity: The object has a force of gravity acting on it due to its mass. This is calculated using the formula:
* Force (Fg) = mass (m) * acceleration due to gravity (g)
* g ≈ 9.8 m/s²
* Net Force: The net force acting on the object is the difference between the force of gravity and the force exerted by the object (which is what we're trying to find).
* Newton's Second Law: This law states that the net force acting on an object is equal to its mass times its acceleration.
Calculations
1. Calculate the force of gravity (Fg):
* Fg = 20 kg * 9.8 m/s² = 196 N (Newtons)
2. Calculate the net force (Fnet):
* Since the object is accelerating downwards, the net force is the difference between the force of gravity and the force exerted by the object.
* Fnet = Fg - Force_exerted
3. Apply Newton's Second Law:
* Fnet = m * a
* Fg - Force_exerted = 20 kg * 4 m/s²
* 196 N - Force_exerted = 80 N
4. Solve for Force_exerted:
* Force_exerted = 196 N - 80 N = 116 N
Answer: The magnitude of the force exerted by the object is 116 Newtons.
