2.2 Flashcards
What is force?
A force is a push or pull acting on an object
How do you work out the resultant force?
If forces act in the same direction you add + if they act opposite you subtract -
What is inertia?
The resistance of any object to a change in its state of motion or rest
What does the mass of an object dictate?
How easy/ difficult it is for an object to move/ change the motion of an object
What is newtons first law of motion?
An object at rest stays at rest, or an object in motion stays in motion with the same speed and in the same direction, unless acted upon by an unbalanced force
What is newtons second law of motion?
F= m x a
What is newtons third law of motion?
For every action (force) in nature there is an equal and opposite reaction
What is weight?
The force of gravity acting on mass of an object
What is mass?
The quantity of matter in an object
What is terminal velocity?
The constant velocity reached by a moving object when the resultant force acting on it (in the direction it is moving) is zero
What happens when the forces are not equal on a parachuter? (1)
1- Weight is bigger than air resistance, parachutist accelerates (no air resistance because parachute is closed)
What happens when the forces are equal on a parachuter? (2)
2- Weight= air resistance, the parachutist is travelling as a constant speed
What happens when the forces are no longer equal? (3)
3- Air resistance is bigger than weight, parachutists is decelerating (more air resistance because parachute is open)
What happens when the forces are equal again? (4)
Weight= air resistance, parachutist reaches terminal velocity again at about 15mph (safe to hit ground)
