What is the force due to resistance by air molecules in the Millikan experiment?

The density of air is a known value. The droplet also experiences a drag force that opposes its motion. This is also called air resistance and occurs as a consequence of friction between the droplet and the surrounding air molecules.

How do you find Net Force with air resistance?

The net external force is equal to the difference between the weight and the drag forces (F = W – D). The acceleration of the object then becomes a = (W – D) / m .

What is the force due to air resistance?

In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid.

How do you calculate the force of air drag?

For larger objects (such as a baseball) moving at a velocity v in air, the drag force is given by FD=12CρAv2 F D = 1 2 C ρ A v 2 , where C is the drag coefficient (typical values are given in Table 1), A is the area of the object facing the fluid, and ρ is the fluid density.

What did the Millikan experiment determine?

Millikan oil-drop experiment, first direct and compelling measurement of the electric charge of a single electron. Millikan was able to measure both the amount of electric force and magnitude of electric field on the tiny charge of an isolated oil droplet and from the data determine the magnitude of the charge itself.

How did Robert Millikan determine the charge of an electron?

In 1909, Robert Millikan and Harvey Fletcher conducted the oil drop experiment to determine the charge of an electron. They suspended tiny charged droplets of oil between two metal electrodes by balancing downward gravitational force with upward drag and electric forces.

How do you calculate resistance force?

Starts here2:072 POE Levers: Calculating Resistance Force – YouTubeYouTube

What factors determine the air resistance force on an object?

The amount of air resistance an object experiences depends on its speed, its cross-sectional area, its shape and the density of the air. Air densities vary with altitude, temperature and humidity.

How do you calculate projectile motion with air resistance?

Mathematically, the resistive force represented by the vector F can be written as F=-f(v) u, where u=V/|V| is the unit vector along the direction of the velocity V. The minus sign guarantees that the air resistance acting on the projectile is always opposite to the direction of its velocity.

How do you find the resistance force in physics?

Newton’s Second Law of Motion: The rate at which the momentum of a body changes with respect to time is equal to the resultant force acting on the body. m d v d t = F . m d v d t = m g + ( − F R ) or m d v d t = m g − F R , where represents this resistive force.

How was Millikan able to determine the charge on the electron?

Robert Millikan’s oil-drop experiment. By comparing applied electric force with changes in the motion of the oil drops, he was able to determine the electric charge on each drop. He found that all of the drops had charges that were simple multiples of a single number, the fundamental charge of the electron.

What did Millikan determine the mass of an electron was?

In 1909, Robert Millikan and Harvey Fletcher conducted the oil drop experiment to determine the charge of an electron. The density of the oil was known, so Millikan and Fletcher could determine the droplets’ masses from their observed radii (since from the radii they could calculate the volume and thus, the mass).

How did Millikan determine the weight of the drop?

Millikan allowed the drop to fall through the air to find the weight of the drop. It reaches its terminal velocity quickly. At this point, the weight is balanced by the viscous drag of the air. Drag can be calculated from the Stokes’ Law, which allowed Millikan to determine the weight.

What is the force of air resistance of an object?

v = Velocity of the object The air constant, or the drag coefficient of the object, is dependent on the shape of the object and is a dimensionless quantity. In case of larger objects at higher velocities, the force of air resistance (F air) is given as, Fair = -½cρAv2

What is the light used in Millikan’s experiment?

A light is used to illuminate the cell and the experimenter can observe within the cell by looking through a microscope. The apparatus used for Millikan’s experiment (shown from two perspectives). As an object falls through a fluid, such as air or water, the force of gravity will accelerate the object and speed it up.

How did Millikan calculate the charge on an electron?

Millikan used a simple apparatus in which he balanced the actions of electric, gravitational, and air drag forces. Using the apparatus, he was able to calculate the charge on an electron as 1.60 × 10⁻¹⁹ C. The Millikan experiment is complicated and fiddly while performing in school.