Resultant Force
- the overall force acting on an object
- (sum of all forces combined)
Newton's First Law
- if there is a resultant force, an object will accelerate or decelerate
- if there is no resultant force, an object will
- remain stationary, or
- continue at a constant speed
Skydiver reaching terminal velocity
- first, their weight is bigger than the upward resistance force.
- this causes them to accelerate downwards.
- then, the resistance increases (they are hitting the wind faster)
- eventually, weight = resistance.
- this causes them to fall at a constant speed.
Car reaching terminal velocity
- first, driving force is bigger than the resistance force.
- this causes the car to accelerate forwards.
- then, the resistance force increases
- eventually, driving force = resistance force
- this causes the car to continue at a constant speed.