4.5.1 Forces and their Interactions Flashcards
Which force acts against moving objects that move through the air?
Drag/Air Resistance
What is a contact force?
A contact force is one that must be in contact with the object to produce a force.
What is a non-contact force?
A non-contact force is one that does not need to be in contact with the object to produce a force.
Is weight a contact or non-contact force?
Non-contact
Is air resistance a contact or non-contact force?
Contact
How is upthrust produced?
Particles at the bottom of a body of water are more compact. When a boat is placed in the water, it exerts a force upwards.
As soon as a parachutist jumps out of a plane, what happens in terms of forces? How does that change the person’s speed?
Weight is larger than air resistance (unbalanced) so the person accelerates.
Why does a parachutist reach terminal velocity? What has to happen to get there?
Terminal velocity is when something is at maximum speed and cannot accelerate further. When speed increases, drag increases to equal the forward force because you hit more air particles over the same time.
