quiz phydicd

Centripetal Force

The force that keeps an object moving in a circle, calculated as F_c = mv^2/r.

Net Force at Top of Vertical Circle

The net force at the top is given by Fnet = Fg + F_n = mv^2/r.

Net Force at Bottom of Vertical Circle

The net force at the bottom is given by Fnet = Fn - F_g = mv^2/r.

Minimum Speed in a Vertical Loop

The minimum speed to stay in a vertical loop is calculated as v = √(gr).

Effect of Speed < √gr at Top of Loop

If the speed is less than √(gr) at the top of the loop, the object will fall out.

Normal Force/Tension at the Top of a Vertical Circle

Calculated as F_n = mv^2/r - mg.

Normal Force/Tension at the Bottom of a Vertical Circle

Calculated as F_n = mv^2/r + mg.

Negative Normal Force Meaning

A negative normal force indicates that the object is airborne and not in contact with the surface.

Scale Reading in Rollercoaster Problems

In rollercoaster problems, the scale reads the normal force.

Speed Calculation at Bottom of Swing

Calculated using: T - mg = mv^2/r, solving for v gives v = √((T - mg)r/m).

Circular Motion Requirement

In circular motion, the net force always points toward the center of the circle.

Units for Mass

Mass should always be measured in kilograms (kg).

Units for Speed

Speed should always be measured in meters per second (m/s).

Units for Force

Force should always be measured in Newtons (N).