Physics - Chapter 3 Test Flashcards
What are the 4 forces acting on a projectile?
1) Upward force
2) Horiz force
3) Gravity (downward force)
4) Friction
What variables affect how dar the projectile will travel?
Launch angle, air resistance, mass and initial velocity
The greater the force applied to an object the…its acceleration
greater
The greater the mass of an object, the….its acceleration
less
Friction is a force that….motion
opposes
When an object is at rest, the applied force is …to the friction force
equal
When an object is accelerating, the applied force is… the friction force
greater than
When an object is moving at a constant velocity, applied force is…the friction force
greater than
Acceleration is….to force
Directly proportional
Acceleration is…to mass
Inversely proportional
Acceleration equation
a=f/m (Newton’s 2nd Law of Motion)
Force equation
F=ma
Weight equation
weight=(mass)(accel. of gravity)
When an object is not accelerating…
The motion isn’t changing
- At rest
- Constant velocity
- at equilibrium
- balanced forces
When an object is accelerating….
The motion is changing
- Speed up/ slow down
- Change direction
- Not at equilibrium
- Unbalanced forces
Friction force is…to the normal force
Proportional
What is static friction?
Friction on an object at rest
What is kinetic friction?
Friction acting on an object while its moving
Also called sliding friction
Always less than static friction
How many times greater is the normal force than the mass?
10 (multiply by 10)
What is the coefficient of friction?
Relationship btwn friction force needed to move something, and the normal force
The normal force means…
Acting perpendicular to surface –> support force
Static friction equation
Fstatic=us x N
Kinetic friction equation
Fkinetic=uk x N
Pressure formula
Force/area
