Chapter 2: Introduction to Forces Flashcards
What is a force?
A force is something that changes an objects speed, shape or direction
What are non-contact forces?
They are forces that act even when objects aren’t touching
What are three examples of non-contact forces?
- Gravitational forces
- Electrostatic forces
- Magnetic forces
What are contact forces?
They are forces that only act when objects are in contact
What is upthrust?
Upthrust is the upward force pushing up on any floating object
What is reaction?
Reaction is the force that pushes back in response to another force
What is a device for measuring force called?
A forcemeter
What is the unit for measuring forces called?
Newtons
What are the two factors of the force of gravity?
The mass of the two objects and how far apart they are.
What is the force of gravity on an object called?
Weight
What unit is mass measured in?
Kilograms
What is a gravitation field?
It’s a region where a mass experiences force
What is the gravitational field strength of earth?
10 newtons per kilogram
How do you calculate weight?
Weight(N)= mass(kg) x gravitational field strength (N/Kg)
What is air resistance?
Air resistance is the force of the air pushing back on you.
What is the difference between weight and mass?
Mass is the amount of matter in an object while weight is the force it exerts.
What is streamlining?
Streamlining is a method to reduce air resistance by reducing the area in contact with air.
What factors affect air resistance?
- The speed of the object
- The area of the object
Will heavier things fall faster in a vacuum?
No
the weight of an object doesn’t matter in a vacuum
What is a force that keeps an object moving in a circle called?
A centripetal force.
If a centripetal force stops acting on an object, what direction will it go in?
In the direction of it’s tangent.
meaning straight in the direction it was headed in.
What are three forces which can have centripetal force?
- Gravity
- Friction
- Tension
