In-class Quiz #5-1
Find The height a ball rises if it
is thrown straight up at 20 m/s
(use g=10 m/s2)
A. 1 m
B. 10 m
C. 20 m
D. 40 m
E. 100m
v 2 = v 02 + 2a ∆x = 0
At the peak of the throw, so
∆x =
− v02
(20m / s ) 2 400m 2 / s 2
=
=
2(− g ) 2 *10m / s 2
20m / s 2
Answer magnitude is reasonable
and units are correct
In-class Quiz #5-3 – Cannon Ball!
True or False: Launching a projectile at
complementary angles to the horizontal will
result in the same range--that is, distance
traveled on a horizontal surface. Are there any
caveats (restrictions) to this statement?
A. True, no caveats
B. True, but the angles must be less than 90º
C. False
In-class Quiz #5-2 –Find the Angle
The following vectors are added:
A=(2,4) and B=(4,2)
(this notation simply gives the (x,y) components
of the vector)
What angle does the resultant make with the xaxis?
A. 0°
Ay + B y 2 + 4
tan(θ ) =
=
=1
B. 30°
Ax + Bx 4 + 2
C. 45°
D. -30°
E. -45°
In-class Quiz #5-4 – Rescue!
How far before the
plane gets to the
hikers does the
rescuer need to
drop the parcel?
A. 180 m
B. 150 m
C. 120 m
D. 100 m
E. 50 m
30 m/s
125 m
1