kinematics: intro physic 11. what is kinematics? area of physics is the branch of mechanics...
DESCRIPTION
Scalar verses vector: Scalar: a measurement only having magnitude or size Ex: 55 km/hr 25 kg 88 mL Vector: a measurement that has magnitude and direction Ex: 55 km/hr SW 125 m NTRANSCRIPT
Kinematics: IntroPhysic 11
What is kinematics? area of Physics Is the branch of mechanics concerned
with motion without reference to force or mass
Scalar verses vector: Scalar: a measurement only having
magnitude or size Ex: 55 km/hr
25 kg88 mL
Vector: a measurement that has magnitude and direction
Ex: 55 km/hr SW 125 m N
Distance:• is a scalar
quantity which refers to "how much ground an object has covered" during its motion.
• What was this person’s distance?
Start/finish
Position (position vector): Symbol: Location of an object at a given time based off
a point of reference Position vector: starts from the origin of a
coordinate system
d
Displacement: The change or difference between the
final position and the initial position of an object
Symbol: ∆d ∆d = positionfinal – positioninital
∆d = df – di
How are distance and displacement different?
start
finish
45 m
175 m
Time and time interval: Usually the time at which an event
begins is designated 0 (zero) seconds. Time interval: the time elapsed between
two instants of time
∆t= tfinal – tinital
What is the time interval for A to B?
A to D?
C to D?
Speed: Speed = distance__
time
describes how fast something is moving. It is a scalar quantity (does NOT indicate direction)
Example:• While on vacation, Karen traveled a total
distance of 440 km. Her trip took 5 hours. What was her average speed?
speed= d / t s = 440km / 5hr
s = 88km/hr
Average Velocity A vector quantity that describes how fast
and in what direction an object is moving (displacement/time interval)
“rate of change of position”
Vave = ∆d or df - di ∆t tf - ti
Example 1:• A helicopter flies 158 km due south from the
airport to a rescue site and it arrives at the site 26.0 mins later, what is the helicopter’s velocity in km/hr?
ti = 0, tf =26min, di =0km, df=158 km S, Vave=? Convert min to hrs: 26.0 min x1hour =0.433 hr
60min Vave = ∆d
∆t= 158km – 0km 0.433hr – 0 hr
= 367 km/hr
Example 2:• The space shuttle Endeavor is
launched to altitude of 500 000 m North of the surface of the earth. The shuttle travels at an average rate of 700 m/s. How long will it take for Endeavor to reach its orbit?
ti = 0, tf =?, di =0m, df=500 000m N, Vave= 700m/s Finish on board!
Practise: Pg 39# 1, 2 Pg 40 # a, b Pg 41# 1, 2 Pg 45# 2,3