First 5
Motion Can be measured in
meters/second
An object moving art a constant velocity has
zero zcceleration
negative acceleration is the same as
something slowing down
movement can be measured only with reference to something
is assumed to be not moving
The rate of change in velocity is called
acceleration
Speed is measured by
distance and time
an object rolls toward the east at a steady speed of 12m/sec for 3 sec. What distance does it travel?
36m
a unit of distance divided by a unit of time describes
speed
if a runner travels 50m in 5sec his speed is
10m/s
Acceleration can be measured in
m/s/s
our most common frame of reference is
Earth
to calculate velocity you need to know the total
distance time and direction of the motion
In one-half hour, a car traveled 20km. its speed was
40km/hr
an example of constantly changing velocity is
circular motion
The value for average speed can be found by
dividing the total distance by the total time involved
The length between two places is
distance
the product of the mass of a moving object times its velocity is its
momentum
speed that does not change is called
constant speed
a distance time graph for acceleration is always a
curved line
When an object slows
1. its velocity changes
2. its speed changes
3. its momentum changes
all of these
the velocity of an object changes if
either its speed or direction change
to determine speed you need to know the total
distance and time of the motion
acceleration can be calculated by
dividing the change in velocity by the time it took to make that change
Which of the following is accelerating
1. a car traveling 33km/h slows to 25km/hr
2. a car traveling 33km/hr speeds to 42km/h
3. a car traveling 35km/h due north turns east while still traveling 33km/hr
all of these
An automobile travels 30m from its starting point 5 sec its speed is
6m/s