Lab 3 Newton’s Laws PHY250L
Student Name:
Access Code (located on the underside of the lid of your lab kit):
Lab Report Format Expectations
Utilize college level grammar and formatting when answering text based questions.
Report all equations in a proper mathematical format, with the correct signs and symbols.
Submissions with incomplete or improperly formatted responses may be rejected.
Pre-Lab Questions
1. State Newton’s Laws in words.
Newton’s first law says that an object will just stay still or keep moving the same way unless a
force comes in and changes that. The second law is really just saying that how much something
speeds up depends on how hard you push it and how heavy it is. And the third law is just that
whenever one object puts a force on another, the second object pushes back just as hard in the
opposite direction.
2. Consider the masses in Figure 4 to the right.
Draw a Free Body Diagram for:
a. Mass 1
,Lab 3 Newton’s Laws PHY250L
b. and Mass 2.
Figure 4: Free Body Diagram: 2 objects with mass
hanging on a pulley by string.
3. Apply Newton’s 2nd Law, F=ma, to write the force equations for M1 and M2. This will yield two
equations that detail the sum of forces in your free body diagram. You should get two force
equations that describe the Tension in the string (force in the up direction), weight for each
mass (force in the down direction) and accelerations for each mass (a1 and a2).
T - M₁g = M₁a₁
M₂g - T = M₂a₂
4. This results in two equations with three unknowns, which means you would be unable to solve
these problems without a third equation. What is this third equation? (Hint: What is the
relationship between a1 and a2? Remember, acceleration has a direction, and thus a sign.)
a₁ = -a₂
, Lab 3 Newton’s Laws PHY250L
EXPERIMENT 1: NEWTON’S FIRST LAW OF MOTION
Introduction Questions
1. How will this experiment demonstrate Newton’s second law of motion?
What this experiment really shows is that when you suddenly stop the container, the water
inside just wants to keep going like nothing happened. The only reason the water’s motion
changes is because your hand gets in the way and stops it. It’s just a simple way to see that force
and acceleration are connected, like Newton’s second law is all about.
2. Draw a free body diagram of your containers of water from the situation in Part 1 Step 4d. Draw
arrows for the force of gravity, the normal force (your hand pushing up on the container), and
the stopping force (your hand accelerating the container as you stop.)
Student Name:
Access Code (located on the underside of the lid of your lab kit):
Lab Report Format Expectations
Utilize college level grammar and formatting when answering text based questions.
Report all equations in a proper mathematical format, with the correct signs and symbols.
Submissions with incomplete or improperly formatted responses may be rejected.
Pre-Lab Questions
1. State Newton’s Laws in words.
Newton’s first law says that an object will just stay still or keep moving the same way unless a
force comes in and changes that. The second law is really just saying that how much something
speeds up depends on how hard you push it and how heavy it is. And the third law is just that
whenever one object puts a force on another, the second object pushes back just as hard in the
opposite direction.
2. Consider the masses in Figure 4 to the right.
Draw a Free Body Diagram for:
a. Mass 1
,Lab 3 Newton’s Laws PHY250L
b. and Mass 2.
Figure 4: Free Body Diagram: 2 objects with mass
hanging on a pulley by string.
3. Apply Newton’s 2nd Law, F=ma, to write the force equations for M1 and M2. This will yield two
equations that detail the sum of forces in your free body diagram. You should get two force
equations that describe the Tension in the string (force in the up direction), weight for each
mass (force in the down direction) and accelerations for each mass (a1 and a2).
T - M₁g = M₁a₁
M₂g - T = M₂a₂
4. This results in two equations with three unknowns, which means you would be unable to solve
these problems without a third equation. What is this third equation? (Hint: What is the
relationship between a1 and a2? Remember, acceleration has a direction, and thus a sign.)
a₁ = -a₂
, Lab 3 Newton’s Laws PHY250L
EXPERIMENT 1: NEWTON’S FIRST LAW OF MOTION
Introduction Questions
1. How will this experiment demonstrate Newton’s second law of motion?
What this experiment really shows is that when you suddenly stop the container, the water
inside just wants to keep going like nothing happened. The only reason the water’s motion
changes is because your hand gets in the way and stops it. It’s just a simple way to see that force
and acceleration are connected, like Newton’s second law is all about.
2. Draw a free body diagram of your containers of water from the situation in Part 1 Step 4d. Draw
arrows for the force of gravity, the normal force (your hand pushing up on the container), and
the stopping force (your hand accelerating the container as you stop.)
