Lesmahagow High School
Measuring Motion
S3 Physics Summary Notes
Lesson 1: What is meant by “speed”? Speed is the d______________ t_____________ by an object in one second (usually expressed in m________ p____ s__________ (m/s))
For a j________ where the object’s speed is not c__________, the average speed is the total distance travelled d_________ by the total time taken. It is the single speed that r__________ the journey.
WORDS LIST: divided journey distance travelled represents constant metres per second
1|P age
Measuring Motion
Lesmahagow High School
S3 Physics Summary Notes
Lesson 2: Calculating average speed The average speed for a journey is total d__________ travelled divided by total t____ taken.
or
v = d t
,
v d t
- average speed (__/__) - distance (m) - time (s)
(Note: v stands for s_______ because it is sometimes called velocity. The wee l_____ above the v tells us it’s average speed.
WORDS LIST: line time distance m/s speed
2|P age
Lesmahagow High School
Measuring Motion
S3 Physics Summary Notes
Lesson 3: What is meant by instantaneous speed? The instantaneous speed of an object is its speed at a particular i_________. In the s________ l___ we use a special method to measure i______________ speed. This uses a light g_____ and electronic t_______:
The timer starts when the object c_______ the light beam and stops when the beam is u_____.
instantaneous = length of the object speed time on timer
WORDS LIST: gate instant cuts science lab uncut timer 3|P age
Lesmahagow High School
Measuring Motion
S3 Physics Summary Notes
instantaneous
4|P age
Measuring Motion
Lesmahagow High School
S3 Physics Summary Notes
Lesson 4,5: Acceleration A_______________ is the change of s_______ each second measured in metres per second s_________ (m/s²).
acceleration =
or
a = v t
change in speed time for change
,
a - acceleration v - “c______ i__” speed t - time
WORDS LIST: squared Acceleration change in speed
5|P age
Lesmahagow High School
Measuring Motion
S3 Physics Summary Notes
Lesson 6,7: Speed-time graphs S_______ t_____ g_______ are very useful for examining motion. They are a visual r________ of an object’s speed as t______ passes.
Examples Speeding up (a_____________)
S_________ speed (constant speed)
S_________ d______ (decelerating)
WORDS LIST: Slowing down record Speed time graphs Steady time accelerating
6|P age
