Physics OAT questions and answers
linear motion--free fall - when the ball is at the max height, the velocity v is 0. The
max height the ball reaches above the ground is found by using:
vf^2=vi^2+2ay
projectile motion - obj has a velocity and position in both vertical and horizontal
directions. no acceleration in the x direction, so particle moves with constant
horizontal speed
Force - Vector quantity. Units: N (kg*m/s^2)
F=ma
mass and weight - mass (m)-scalar
weight (w)-force vector
W=mg
unit: N
Newton's laws of motion - 1. A body in motion will stay in motion
2. A net force applied to a body of mass m will result in that body undergoing
acceleration. F=ma
3. For every action there is an equal and opposite re-action
,Physics OAT questions and answers
moment of force/torque τ - τ=rFsin(θ)
minimum torque occurs when theta=0
centripetal acceleration--does not change the speed of obj - a=v^2/r
centripetal force--magnitude of the centripetal force on a particle - F=ma=mv^2/r
elevator probs - while elevator is accelerating upward, the tension in the cable
must be greater than the maximum weight so that the difference produces a
nonzero acceleration.
while elevator is moving at a constant speed, its acceleration is zero, so net force
on the elevator is also zero, so the tension and weight are equal.
frictional force - Obj sliding down--the normal force decreases as the angle of the
incline increases. frictional force decreases as the angle of the incline increases
relationship of velocity and time of revolution - v=2πr/T
Box up an incline: solving for perpendicular force - F=mg*cosθ
,Physics OAT questions and answers
Box up an incline: solving for parallel force - F=mg*sinθ
Work done by F - W=Fdcosθ
Power - P=W/t
Unit: Watts (1 J/sec)
P=Force * Velocity
P= Current (I) *V (volts)
Kinetic energy - K=(mv^2)/2
Units: J
Potential energy - U=mgh
m=mass of the body
g=gravity
h=height
Units: J
, Physics OAT questions and answers
Total mechanical energy - E=K+U
-mechanical energy is conserved when the sum of the potential and KE remains
constant
-mechanical energy is not always conserved though. when friction is present, ME
is drained away in heat
work-energy theorem - W=ΔK=Kf-Ki
PULLEY efficiency: the measure of the amt of work a person puts into a machine
that comes out - Efficiency=W out/W in
W out=(loadxload distance)
W in=(effortxeffort distance)
load=mass of obj*gravity
effort distance=the effort for the load to move through the distance by all pulleys
(ex: if there are 6 pulleys and load must move a distance of 4 m...6 pulleys*4
m=24 (load distance)
momentum - p=mv
linear motion--free fall - when the ball is at the max height, the velocity v is 0. The
max height the ball reaches above the ground is found by using:
vf^2=vi^2+2ay
projectile motion - obj has a velocity and position in both vertical and horizontal
directions. no acceleration in the x direction, so particle moves with constant
horizontal speed
Force - Vector quantity. Units: N (kg*m/s^2)
F=ma
mass and weight - mass (m)-scalar
weight (w)-force vector
W=mg
unit: N
Newton's laws of motion - 1. A body in motion will stay in motion
2. A net force applied to a body of mass m will result in that body undergoing
acceleration. F=ma
3. For every action there is an equal and opposite re-action
,Physics OAT questions and answers
moment of force/torque τ - τ=rFsin(θ)
minimum torque occurs when theta=0
centripetal acceleration--does not change the speed of obj - a=v^2/r
centripetal force--magnitude of the centripetal force on a particle - F=ma=mv^2/r
elevator probs - while elevator is accelerating upward, the tension in the cable
must be greater than the maximum weight so that the difference produces a
nonzero acceleration.
while elevator is moving at a constant speed, its acceleration is zero, so net force
on the elevator is also zero, so the tension and weight are equal.
frictional force - Obj sliding down--the normal force decreases as the angle of the
incline increases. frictional force decreases as the angle of the incline increases
relationship of velocity and time of revolution - v=2πr/T
Box up an incline: solving for perpendicular force - F=mg*cosθ
,Physics OAT questions and answers
Box up an incline: solving for parallel force - F=mg*sinθ
Work done by F - W=Fdcosθ
Power - P=W/t
Unit: Watts (1 J/sec)
P=Force * Velocity
P= Current (I) *V (volts)
Kinetic energy - K=(mv^2)/2
Units: J
Potential energy - U=mgh
m=mass of the body
g=gravity
h=height
Units: J
, Physics OAT questions and answers
Total mechanical energy - E=K+U
-mechanical energy is conserved when the sum of the potential and KE remains
constant
-mechanical energy is not always conserved though. when friction is present, ME
is drained away in heat
work-energy theorem - W=ΔK=Kf-Ki
PULLEY efficiency: the measure of the amt of work a person puts into a machine
that comes out - Efficiency=W out/W in
W out=(loadxload distance)
W in=(effortxeffort distance)
load=mass of obj*gravity
effort distance=the effort for the load to move through the distance by all pulleys
(ex: if there are 6 pulleys and load must move a distance of 4 m...6 pulleys*4
m=24 (load distance)
momentum - p=mv
