a
=
Based on your answers to the previous parts, what conclusion can you draw about the
acceleration of the cart?

(b) Consider the situation when friction force is non-zero. What is the expression for the
acceleration of the cart now? (Use the following as necessary:
m
1
,
m
2
,
f
, and
g
.)

If you now
triple
the hanging mass
m
1
, (so
m
=
3
m
1
) how will the value of the denominator for
the expression for the acceleration change?
.

What is the expression for the acceleration now? (Use the following as necessary:
m
1
,
m
2
,
f
, and
g
.)

Based on your answers to the previous parts, what conclusion can you draw about the
acceleration of the cart?

11/25/11 8:54 PM
Lab 3 - Newton's Second Law: PostLab
Page 5 of 9
4.
10/10 points |
Previous Answers
In the diagram below,
indicates the pulling force and
the friction force acting on the object. The
direction of motion of the object is indicated by the velocity vector
Figure A
Figure B
Figure C
For each case, indicate the direction of the net force, the direction of the acceleration of the object and
state whether the object is speeding up, slowing down, or moving with constant velocity. The force
vectors are drawn to scale.
Direction of net force
Direction of acceleration
The object is
A
to the left
to the left
slowing down
B
to the right
to the right
speeding up
C
The net force is zero.
The acceleration is zero.
moving with constant velocity
A simple Atwood machine consists of two masses
m
1
and
m
2
that are connected by a string wound over
a pulley, as seen in the figure below. Assume
m
2
is larger than
m
1
. Motion in the upward direction is
positive. On a piece of paper, draw two free body diagrams; one for each of the masses, showing all
forces acting on each mass. Then answer the following questions.
.
5.
10/10 points |
Previous Answers