Physics 111A - Lab Report
Lab 112: Newton’s Second Law
Introduction
The purpose of this experiment was to investigate the relationship between forces, mass, and
acceleration described by Newton’s Second law. In our experiment we explored these
relationships. Another purpose of this experiment was to learn how to construct and use free
body diagrams illustrating all forces with the magnitude and direction acting on an object to
predict the acceleration of an object in a given system.
Theoretical Background
Newton’s first law of motion states that an object at rest will stay at rest and an object in motion
will remain in motion unless a net force acts upon the object. Newton’s second law states that the
acceleration of an object is directly proportional to the force acting and inversely proportional to
the mass of the object. Direction of the acceleration is in the direction of the net force acting on
the object. Newton’s second law can be written as:
a = acceleration of the object (vector)
m = mass of the object
∑ 𝐹= net force on the object (vector)
∑ 𝐹x = max ; ∑ 𝐹y = may ; ∑ 𝐹z = maz
This experiment tests Newton’s Second Law in a frictionless system with one-dimensional
motion. A cart of mass M is on a track. The cart is connected by a string that goes over a pulley
to a hanging mass (m). Gravity pulls the hanging mass down, making tension in the string and
accelerating the cart along the track.
, Theoretical acceleration of the cart can be found:
𝑎 = 𝑚𝑔/𝑀 + 𝑚
On the inclined plane:
Lab 112: Newton’s Second Law
Introduction
The purpose of this experiment was to investigate the relationship between forces, mass, and
acceleration described by Newton’s Second law. In our experiment we explored these
relationships. Another purpose of this experiment was to learn how to construct and use free
body diagrams illustrating all forces with the magnitude and direction acting on an object to
predict the acceleration of an object in a given system.
Theoretical Background
Newton’s first law of motion states that an object at rest will stay at rest and an object in motion
will remain in motion unless a net force acts upon the object. Newton’s second law states that the
acceleration of an object is directly proportional to the force acting and inversely proportional to
the mass of the object. Direction of the acceleration is in the direction of the net force acting on
the object. Newton’s second law can be written as:
a = acceleration of the object (vector)
m = mass of the object
∑ 𝐹= net force on the object (vector)
∑ 𝐹x = max ; ∑ 𝐹y = may ; ∑ 𝐹z = maz
This experiment tests Newton’s Second Law in a frictionless system with one-dimensional
motion. A cart of mass M is on a track. The cart is connected by a string that goes over a pulley
to a hanging mass (m). Gravity pulls the hanging mass down, making tension in the string and
accelerating the cart along the track.
, Theoretical acceleration of the cart can be found:
𝑎 = 𝑚𝑔/𝑀 + 𝑚
On the inclined plane:
