PHYSICS WITH MR. TALBOO
WARM-UP (2D Motion Introduction)
NAME: ____________________________
DATE: ______________ PERIOD: _____
In the Iphone App “Angry Birds”, a player
launches a big red bird at its target. The initial
velocity of the bird is 2 m/s @ 40°.
a) Find the x and y components of the velocity
vector using trigonometry.
θ
Vx = V cos θ = 2 cos 40 = 1.532 m/s
Vy = V sin θ = 2 sin 40 = 1.286 m/s
b) Using the vertical velocity from above as
your initial velocity, calculate the total time
the bird is in the air. This is simply a freefall problem!
∆y
DATA TABLE
vi
vf
g
1.286
-1.286
9.8
t
?
t = (Vf – Vi) / -g
= (-1.286 – 1.286) / -9.8
t = 0.262 s
c) Use the horizontal velocity from a) and the time from b) to find how far the big red bird traveled.
∆x
?
DATA TABLE
vi
vf
a
1.532
-----
0
t
0.262
∆x = Vit + ½ at2 = (1.532)(0.262) + (0.5)(0)(0.262)2 = 40.1 m
d) What happens to a freely-falling object’s speed as it falls, assuming there is no air resistance?
It will accelerate at a uniform rate of -9.8 m/s2.
e) What happens to a freely-falling object’s speed as it falls in the presence of air resistance?
It will accelerate at a uniform rate of -9.8 m/s2 until it reaches its terminal velocity.