Distance/Displacement
The distance between an object and a reference point is the object's_________
position
What is the equation for momentum?
p=mv
Average speed is found by __________
dividing total distance traveled by the total time.
What is the formula for acceleration?
a=Vf-Vi/time
Define the term centripetal acceleration
Centripetal acceleration is acceleration toward the center of a curved or circular path.
At 8:00 AM you leave home and walk 0.5 km to a friend's house. At 11:30 AM you return home, then travel by car to the mall, which is 10 km away, and arrive at 11:45 AM. What is the total distance traveled?
11 km
.5+.5+10=11km
Describe how velocity and speed are different.
Velocity includes direction; speed does not.
_________ is the speed of an object at any instant of time.
Instantaneous speed
Identify three ways an object can accelerate.
speed up, slow down, change direction
Determine the change in velocity of a car that starts at rest and has a final velocity of 20 m/s north.
change in velocity = 20m/s north
Describe the difference between the total distance traveled and the displacement.
The total distance traveled is the length an object travels along its path; displacement is the distance and direction from the starting point to the stopping point.
The direction and speed of an object is described by its_________
velocity
A passenger elevator travels from the first floor to the 60th floor, a distance of 210 m, in 35 s. What is the elevator's speed?
s=d/t
210 m/35 s=6.0m/s
As you break your bicycle, your velocity changes from 20 east m/s to 10 east m/s in 5 seconds. What is your acceleration?
2 m/s2 west
What is a subterranean vehicle?
A vehicle that operates underground.
Determine the total displacement of a dog that runs 15 m north, 6 m south, then 8 m north.
17 m north
(15m North-6m South)+8 North=17m North
When directions are opposite you subtract. The direction of the total displacement is always the direction of the larger displacement.
If an object has a constant velocity, then it________
has an acceleration of zero
A motorcycle is moving at a constant speed of 40 km/h. How long does it take the motorcycle to travel a distance of 10 km?
10 km/40 km/h= .25 h or 15 min
When the equation for speed is rearranged, we have t=d/s
Which best describes why projectiles move in a curved path?
They have a constant horizontal velocity and vertical acceleration.
Analyze the motion of an object that has an acceleration of 0 m/s2?
It has a constant velocity. That is, it is moving in a straight line with constant speed or is at rest.
Explain whether an object's displacement could be greater than the distance the object travels.
No. The displacement equals the distance only if the object moves in a straight line in a single direction. Otherwise, the displacement is less than the distance.
A change in velocity means a change in________
speed, direction, or both
Identify two common ways of expressing a changing speed.
Explain why you cannot use the acceleration equation
Accelerations that are not in the same or opposite directions cannot be directly combined.
Describe a car's velocity as it goes around a track at a constant speed.
The magnitude of the car's velocity is constant, but the direction is constantly changing.