Describing Motion
What does the study of kinematics describe?
the motion of objects
What is the common name for uniformly motion influenced by gravity only?
free fall
On a position-time graph, what does a steep slope meant?
faster speed/velocity
Is displacement a vector or scalar quantity?
vector
A sprinter runs 50 m in 4.90 seconds. What is his average velocity?
10.2 m/s
What is the difference between speed and velocity?
Speed is rate of change in distance; velocity is rate of change in displacement (vector quantity)
displacement
On velocity-time graph, what does the slope represent?
acceleration
What does instantaneous velocity refer to?
velocity at specific instant in time
If an object travels 20 m in 5 seconds, what is their average speed?
4 m/s
What kind of motion does a horizontal line on a velocity-time graph represent?
constant velocity
Which equation allows you to find displacement without knowing time?
x_f=x_i+((v_f)^2-(v_i)^2)/(2a)
Describe position-time graph where object is stationary.
horizontal line
What is meant by uniform acceleartion?
acceleration that does not change over time
What is the displacement of an object accelerating at 20 m/s^2 in 4 seconds?
40 m
What term describes the rate of change in an object's velocity?
acceleration
Which equation should you use to calculate final velocity with known acceleration and time?
v_f=v_i +a/_\t
Describe position time graph where object is accelerating.
What is the displacement of an object that travels in one direction and then returns to its starting point?
zero
If a car brakes from 25 m/s to 0 m/s in 5 seconds, what is the acceleration?
- 5m/s^2
What does the slope of a position-time graph represent?
velocity
Solve: A car accelerates uniformly form 0 to 60 m/s in 5 seconds. What is its acceleration?
12 m/s^2
Using a velocity-time graph, how can you find the total displacement?
area under the curve or can solve it algebraically
What is the area under an acceleration-time graph?
velocity
A runner is 65 m from the door, running at 8.0 m/s and another runner is at 7.0 m/s. How far ahead is the faster runner when they read the door?
8.125 m