Download 4.01B Michelle was learning about forces today in her science class

Name: ______________________________________ Date____________ Class: ___________________
4.01B
Michelle was learning about forces today in her science class. On the car ride home, she started
wondering about the forces acting on the car. She wondered in what situations there could be
balanced forces on it.
1. If the forces are balanced,
a.
b.
c.
d.
The
The
The
The
car would have to be slowing down.
car would have to be moving at a constant speed.
car would have to be at rest (stopped).
car could be moving at a constant speed or be at rest.
2. If the car was moving at a high constant speed, which of the following statements must be true?
a. The forces are balanced.
b. There is an unbalanced force in the direction of motion.
Michelle’s car broke down on the way home, and she had to push it off the road. As she pushed the
car off the road, it moved with a constant velocity.
1. While it moved with constant velocity, which of the following must be true?
a. Michelle’s forward
on the car).
b. Michelle’s forward
earth on the car).
c. Michelle’s forward
d. Michelle’s forward
push was equal to the weight of the car (gravitational force by the earth
push was greater than the weight of the car (gravitational force by the
push was greater than the backward resistance of friction.
push was equal to the backward resistance of friction.
2. Explain your answer. Draw a force diagram to go with your explanation:
Explanation:
Force Diagram:
4.02A
Forces
Balanced?
A box is motionless on a
ramp.
Draw the forces on the box.
A box slides across an ice rink
without friction. It moves
with a constant velocity
Draw the forces on the box.
Spiderman swings from
between two buildings,
moving at a constant
velocity.
Draw the forces on Spidey.
A box is motion is on a ramp
with a cord attached to the
top.
Draw the forces on the box.
System Schema
Free Body Diagram
4.03C
According to Newton’s third law, list the “equal and opposite force” for each of the following.
1. A girl pushes a desk across the room at a constant velocity
List ALL of the forces acting on the desk, and name their 3rd law pairs:
Force – write each force with ALL of the
subscripts
What is the “equal and opposite” force according
to Newton’s 3rd law
Doug and Amy lean back, pulling on each other. Doug weighs 180 pounds, and Amy weighs 120
pounds.
2a. Which one pulls harder on the other, if they do not move?
2b. In the example above, who exerts a greater force if Doug moves backward?
2c. In the example above, who exerts a greater force if Amy moves backward?
4.04A
A man pushes a giant box to the left at a constant speed. The box
has a mass of 48 kg and is being pushed with a force of 220
Newtons.
1. For your own reference, draw the force diagram for the box.
TOTAL
YComponent
Force
X-Component
2. Complete the force table below.
3. Draw a quantitative force diagram on the graph paper below, using a scale of 1 cm = 50 N.
Be sure to draw arrowheads on your vectors and label them!!
4.05B
A person PUSHES on a 30 kg stroller with a 200 N force acting at
a 35° angle with the horizontal. The stroller moves with
constant velocity.
35º
1. For your own reference, draw a qualitative force diagram for
the stroller:
TOTAL
Y-Component
Force
X-Component
2. Complete the force table below.
3. Draw a quantitative force diagram on the graph paper below, using a scale of 1 cm = 50 N.
Be sure to draw arrowheads on your vectors and label them!!
4.06C
Winkin, Blinkin, and Nod are being pulled down a hill on a
sled by their older brother Drowsy. They are traveling t a
constant velocity of 5 m/s! Here’s all you know…
A. (Target 4.02A) Sketch a
system schema for the
sled in the space below.
55°
B. (Target 4.02A) Draw a qualitative force diagram for the sled in the
space below. Label the forces with the three subscripts (e.g.
Fg/earth/box). Draw a rotated force diagram and indicate how much
you rotated and in which direction.
Fill in the force table on the right.
SHOW ALL OF YOUR WORK ON THE FOLLOWING
PAGE.
Force
(You may not need all of the spaces.)
TOTAL
YComponent
•
•
Drowsy exerts a 150 N force on the sled (down the
hill).
The hill is at an angle of 55° above the x-axis.
The total mass of the kids and sled is 50 kg. The sled
moves with constant velocity
XComponent
•
REQUIRED: On this page, show all of your work (what you did to fill in the force table) LABEL
EVERYTHING Suggested scale of 1 cm = 50 N.
Math and Conversions: