2: Forces Flashcards
Normal contact force
If a body touches another body
Drag forces
Oppose the motion of a body through a fluid
Friction
When a body slides over another
Friction laws
1) Area of contact doesn’t affect the force
2) Its directly proportional to the normal
3) Force doesn’t depend on speed
Equilibrium
Resultant force is 0
Newton’s 1st law of motion
When the net force on a body=0 the body will move with a constant velocity in a straight line.
Inertia
Keeps the body in the same state of motion when no forces act on the body.
Newton’s 3rd law of motion
If body x exerts a force on body Y, then body Y will exert an equal and opposite force on body x.
Free fall
- Net force of a free body = w
- W = mg
- ∑f= W
- w = m x a
- mg = ma
- g = a
What does a circular motion require?
The presence of a force directed towards the centre of the circle
What is T in circular motion?
Period of a motion: How long it takes for 1 full revolution
In circular motion what happens in theres a small angle?
The arc length and s are equal.
How do you get the formula for the distance travelled in circular motion
- Get the velocity of the object in two points
- Draw 2 velocity tangents
- Draw an isosceles triangle
- Get the arc length
- L= angle x radius
- 𐤃v= v x 𐤃angle
- a= 𐤃v/𐤃t
- a = v𐤃angle/t
- a = v x w
