2-D MOTION
Physics 111
YOU ARE ADDING VECTORS OF LENGTH OF 20
AND 40 UNITS. WHAT IS THE ONLY POSSIBLE
RESULTANT MAGNITUDE?
A)18
B)
37
C) 64
D) 100
ANSWER: 37
 If
scalar, Max value is 60 units
 If scalar, min value is 20
 Says
the value is a Vector, so have
different directions
 Has to be between 60 and 30
37 Is the only option that works
ADDING VECTORS
 Add
the following vectors and
determine the resultant.
 5.0 m/s, 45 deg and 2.0 m/s, 180
deg
MAG: 3.85
AT 66.5 DEGREES FROM –X AXIS
ADD THE FOLLOWING VECTORS AND
DETERMINE THE RESULTANT.
3.0
m/s, 45 deg and 5.0
m/s, 135 deg and 2.0 m/s,
60 deg
ANSWER: 7.40 M/S @ 93.2 DEGREES
PROBLEM:
During
the Vector Addition lab,
Mac and Tosh start at the
classroom door and walk 40.0 m,
north, 32.5 m east, 15.5 m south,
68.5 m west, and 2.5 m, north.
Determine the magnitude and
direction of the resultant
displacement of Mac and Tosh.
ANSWER:

45.0 m, 36.9° N
GIVEN THAT A + B = C, AND THAT
LAL 2 + LBL 2 = LCL 2, HOW ARE
VECTORS A AND B ORIENTED WITH
RESPECT TO EACH OTHER?
1) they are perpendicular to each other
2) they are parallel and in the same
direction
3) they are parallel but in the opposite
direction
4) they are at 45° to each other
5) they can be at any angle to each other
ANSWER: THE ARE PERPENDICULAR
Vectors
satisfy the
Pythagorean Theorem, with
suggest they are a right
triangle, where a and b
would be perpendicular at a
90 degree angle
GIVEN THAT A + B = C, AND THAT LAL +
LBL = LCL , HOW ARE VECTORS A AND B
ORIENTED WITH RESPECT TO EACH
OTHER?
1) they are perpendicular to each other
2) they are parallel and in the same
direction
3) they are parallel but in the opposite
direction
4) they are at 45° to each other
5) they can be at any angle to each other
ANSWER: PARALLEL BUT IN SAME
DIRECTION
The
only time vector
magnitudes will simply
add together is when the
direction does not have to
be taken into account
A CERTAIN VECTOR
HAS X AND Y
COMPONENTS THAT ARE EQUAL IN
MAGNITUDE.
WHICH OF THE FOLLOWING
IS A POSSIBLE ANGLE FOR THIS VECTOR,
IN A STANDARD X-Y COORDINATE SYSTEM?
1) 30°
2) 180°
3) 90°
4) 60°
5) 45°
ANSWER:
 The
45
angle of the vector is given
by tan q = y/x. Thus, tan q = 1 in
this case if x and y are equal,
which means that the angle must
be 45°.