physics 2 Flashcards
rate
quanitity divided by time
per
divided by
speed
a measure of how fast something is moving
velocity
how fast something moves and in which direction
How are all things, even those that appear to be a rest, really in motion?
The earth is always moving and so when we see something that appears at rest, in reality, with the sun as a relative point, it is moving.
Describe what it means that motion is relative.
In respect to an object, ex. a car moves in respect to the road.
What is the formula for (average) speed?
Distance / time
If a cruise ship covers 600 miles during the period of an entire day, what was the cruise ship’s speed?
600/24=25 mph
The trip from MLS to Liberty Township, Ohio, is 317 miles. If a student makes that trip in 4.5 hours what was their average speed?
70 mph
A nonstop flight from Saginaw to Wethersfield, CT, would take 1 hour and 50 minutes and travel at an average speed of 320 mph. About how far away are the two cities from each other? (Be careful with the time! You have to change hours and minutes to just hours.)
320 x 1.83=585.6 miles
What is the formula for acceleration?
Change in velocity / time
The Falcon 9 SpaceX rocket has a burn time of 397 secs and travels a distance of 83,000 m in that time. What was its average speed? What was its acceleration?
Speed = 83,000/397 = 209 m/s
Acceleration = 209/397 = 0.53 m/s/s
The car accelerated from 30 m/s to 60 m/s in 4.5 seconds. What is the rate of acceleration?
Acceleration = (60-30)/4.5 = 6.67 m/s/s
What is an object’s instantaneous speed after 1 sec? 5 sec? 19 sec? (with no air resistance)
10 m/s, 50 m/s, 190 m/s
How far has an object fallen after 1 sec? 5 sec? 19 sec? (with no air resistance)
5 m; 125 m; 1,805 m
