Constant speed
A Data Table
Time
0 sec
Position
1 meter
Velocity
= dist/time & direction
1 sec 2 meters 1 m/s to right
2 sec 3 meters 1 m/s to right
3 sec 4 meters 1 m/s to right
constant velocity
Position-Time Graphs
Dis
tanc
e in
Fee
t
Time in Seconds0 1 2 3 4 5 6 7 8 9
40
120
160
200
80
Describes the Rate of Change in Position of an Object Over Time
Distance (ft) Vs. Time (sec.)
Position-Time Graph
Dis
tanc
e in
Fee
t
Time in Seconds0 1 2 3 4 5 6 7 8 9
40
120
160
200
80
Distance (ft) Vs. Time (sec.)
The Slope of this Line Remains Constant Throughout the Graph
The constant slope indicates that the speed of the object remains constant
Position-Time Graph
Dis
tanc
e in
Fee
t
Time in Seconds0 1 2 3 4 5 6 7 8 9
40
120
160
200
80
The Speed of This Object
Changes Over Time
Distance (ft) Vs. Time (sec.)
B
C
A
Speed @C = 50 ft/secSpeed @A = 5 ft/sec Speed @B = 24 ft/sec
The Object is Accelerating
VelocitySlope
Changes in Velocity
25 m/s, downward
10 m/s, downward
25 meters per second, 45 degrees upward
25 meters per second, 45 degrees downward
Velocity changesin both these cases.
Interpret The Graph Below:
Balanced vs Unbalanced forces
Momentum*Depends on what two things?
a. Massb. Velocity
P = mv
Units – kg. m/s, direction
1. Two hockey players, big Joe and little Tim collide head on and get tangled while going for the puck. 65 kg Tim was travelling at 9.5 m/s while 105 kg Joe was moving at 5.2 m/s.Who will go in which direction, and what is their momentum before the collision?
Interpret The Graph Below:
Interpret The Graph Below:
Interpret The Graph Below:
AccelerationAcceleration
a= v/t a= v/t a=acceleration,v=velocity a=acceleration,v=velocity =change, t=time =change, t=time
*Change in velocity divided by the time *Change in velocity divided by the time interval in which the changed occurredinterval in which the changed occurred
Units - m/s2, direction
A missile was released from an airplane at the velocity of 78 km/hr south and ended up traveling at a velocity of 104 km/hr south. It took the missile 1 hour to reach the target. Find the missile’s acceleration.
1.What do they want to know?2. Which formula do I use.3. Plug in the numbers.
A dog runs with an initial speed of 1.5 m/s on a waxed floor. It slides to a stop with an acceleration of -.35 m/s2 . How long does it take for the dog to stop?
A football player likes to practice knocking the other players of their feet. He has a mass of 624.8 kg and created a momentum of 3124 kg. mph as he flatten a teammate. What was his velocity when he hit his teammate?
1.What do they want to know?2. Which formula do I use.3. Plug in the numbers.
ForceCause of acceleration, or change
in an object’s velocity
F = ma, units – N, newtons1 newton = .225 lb
Net force
Combination of all of the forces acting on an object
Gravity & Friction Gravity Attraction of two particles of matter due to
their mass Mass & Distance effects it 9.8 m/s2
Friction Force between two objects in contact that
opposes the motion of either object
Explain what is happening
Weight Elevator
Is your weight the same on earth as it is on the moon?
Is your mass the same on earth as it ison the moon?
Mr. Dovzak