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Unit 2
Motion and Gravity,Vocab
Question | Answer |
---|---|
How do you observe objects in Motion? | By using a reference point |
explain how two objects can be moving at the same time and speed can have different velocities. | The speed doesn't change, but the "direction" does |
Which of the following is a measurement of velocity? 16 m East, 55 m/h South, 25 m/s2, 60 km/hr | 55 m/h South |
explain how two objects at a constant speed can have a different acceleration. | The speed is constant but the "direction changes" |
what is net force? What is force measured in? | ALL of the forces combined on an object, measured in Newtons. |
What is a speed that stays exactly the same is called? | constant speed |
A change in velocity divided by time calculates what? | acceleration |
an overall increase in acceleration | positive acceleration |
an overall decrease in acceleration is called? | negative acceleration |
All of the total distances divided by time calculates what? | average speed |
an objects change in position relative to a reference point | motion |
what does this describe? 90km/hr | speed |
the speed of an object in a particular direction (km/s East) | velocity |
if the rate of velocity of a car changes, or direction changes, that change is measured as a change in ----- | acceleration |
a push or a pull is a | force |
what unit is force expressed in | Newton |
Friction where no motion is occurring | static friction |
friction where motion is occurring | kinetic friction |
what is the formula for acceleration | a= change in velocity/ time or a= (Vf-Vi)/ t |
what are the two parts of Gravitational Law | Large Mass, and nearness, proximity, increases Gravitational attraction |
what two things cause friction | mass and texture |
the amount of matter in an object | Mass |
a measure of the gravitational pull on an object's mass is called? | Weight |
while falling, gravity is pulling you how fast? | The gravitational tug is to be calculated at 9.8 m/s2 while falling (until you reach terminal velocity) 9.8m/s/s |
how can you reduce friction? | decrease mass per square inch and lubricate or smooth the surfaces |
tell me how an object will move when a net force is applied | there must be a force that is greater than the other forces being applied to create "unbalanced forces", causing movement. ****Balanced forces don't cause movement***** |
what is average speed? | Total distance divided by time |
what is constant speed? | like cruise control it doesn't change |
what is acceleration? | a change in velocity, in speed or direction, over time |
Jeff long-boards to school each day. This week his times were 21 minutes, 22 minutes, 24 minutes,26 minutes and 19 minutes to go 2 miles to school. What is his average speed? | |
Use the following data: Jeff long boards to school and today his time was 44 minutes to go 2 miles to school. What was his speed? | s=d/t |
If a car travels from a stop sign to 10km in 5 seconds, what is the acceleration of the car? | a = vf-vi/t |
Sara swims on the swim team. This week her times in the 200 meter race were 4 min, 4.5 min, 6.2 min,4.2 min and 4.3 min. What was her average speed? | |
What is the speed of a cat that falls 4 seconds? | G*t G= 9.8m/s 2 |
Tommy was sledding and started at the top of a hill. After being stopped and pushing off he reached a speed of 30 m/s at the bottom of the hill. It took him 3 seconds. What was his acceleration? | a=Vf-Vi/t |
What is a Newton? (not the cookie) | A measurement of "Force" that equals 1kg 1m/s/s |
Do you understand ***Free Body Diagrams and how to calculate net force? | You compare all the forces and determine the direction that the item will move. |
Do you understand ***time/distance graphs or time/speed graphs? | See the examples in the daily classwork. They are covered there. |