Module 3: Acceleration and Gravity Flashcards
What is a vector?
A quantity that has both size and direction
Examples:
- John walks north 20 meters. The direction “north” together with the distance “20 meters” is a vector.
- An apple falls down at 10 meters per second. The direction “down” combined with the speed “10 meters per second” is a vector. This kind of vector is also called velocity.
What is acceleration?
The rate at which velocity changes over time
Example:
When you press down on the gas pedal in a car, the car surges forward going faster and faster
What is velocity?
The speed in a particular direction
Example:
If an object moves east at 9 meters per second (9m/s), then its velocity is 9 m/s to the east.
Is velocity a vector?
YES
(Since velocity has both size and direction, it is called a vector quantity.)
What is the speed formula?
s = d/t
What is the acceleration formula?
Vf-Vi
a= ——-
t
a= acceleration (a change in the velocity of the object)
Vf= Final velocity (the speed when an object falling through a fluid (usually air) is no longer getting faster)
Vi= Initial velocity (velocity at which motion STARTS)
t= time
An object cannot be accelerating if it has a constant speed. (TRUE or FALSE?)
FALSE
(Accelerating= changing the velocity (speed + direction), so it CAN NOT have persistent speed)
As a car slows down to stop at a traffic light, we can say the car has…
a. no acceleration
b. positive acceleration
c. negative acceleration
As a car slows down to stop at a traffic light, we can say the car has (C) NEGATIVE ACCELERATION
(because it is slowing down and positive acceleration means to speed up. also no acceleration means it stays the same speed, but it is not.)
____________ always stays the same, but _____________ changes depending on the amount of gravity.
a. Weight, mass
b. Mass, weight
c. Acceleration, velocity
d. Speed, reference point
(B) MASS always stays the same, but WEIGHT changes depending on the amount of gravity.
The acceleration of an object traveling at a constant speed is….
A. Positive
B. Negative
C. Equal to zero
D. None of the above are correct
(C) The acceleration of an object traveling at a constant speed is EQUAL TO ZERO
The acceleration of an object traveling at a constant speed is….
A. Positive
B. Negative
C. Equal to zero
D. None of the above are correct
(C) The acceleration of an object traveling at a constant speed is EQUAL TO ZERO
Are velocity AND accelerations both vectors???
YES VELOCITY AND ACCELERATION BOTH ARE VECTORS
size and direction (vel) + speed in particular direction that changes (a) = quantity that has both size and direction (vec)
What happens when two objects become farther apart from each other?
The gravitational attraction between the objects will…
DECREASE
INCREASE
or
STAY THE SAME
The gravitational attraction between the two objects will DECREASE when they become further apart from each other.
What does it mean when an object has an acceleration of zero?
a. The object is not moving
b. the object is traveling at a constant velocity
c. Both answers are correct
(C) The object is not moving or traveling at a constant velocity when the object has an acceleration of zero.
What is gravitational pull?
A force that ties to pull two objects together
