thomas 2nd law test Flashcards
Bossy newtons first law
if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force.
Bossy newtons second law
the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it. The momentum of a body is equal to the product of its mass and its velocity.
Bossy newtons third law
when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
Towing problem
Net force: (one force take away the other)
Acceleration: F=MA
Rocket problem
Thrust, T, from the rocket increases
Weight of the rocket, MG, decreases
F=T-MG
Elevator problem Lift moving up and accelerating
F=MG
T-MG=MA
1) Lift moving up and accelerating (a>0) T=MG+MA T>MG
Pulling problem
As on goes up, one goes down
For m: T-mG=mA
For M: Mg-t=MA
T-MG = MG -T (M-m)g = (M+m)a
Sliding slope
mgsinθ = force slope down
mgsinθ - friction = ma
mgsinθ - friction = resultant force
Lift problem Lift moving at combined velocity
F=MG
T-MG=MA
2) Lift moving at combined velocity (a=0) T=MG
lift problem Lift, M, moving up and decelerating
F=MG
T-MG=MA
3) Lift, M, moving up and decelerating (a<0) T=MG+MA T(less than) MG
Lift problem Lift accelerating downwards
F=MG
T-MG=MA
4) Lift accelerating downwards (a<0) T=MG+MA T
Lift problem Lift moving down and decelerating
F=MG
T-MG=MA
5) Lift moving down and decelerating (a>0) T=MG+M