DIY - What is a Normal Force?
The normal force is a force exerted by a surface on an object, which is resting against the surface. For example, it is the force exerted by the table on a book kept on it, which prevents the book from falling down due to gravity.
Some characteristics of a normal force are:
- The normal force exerted on an object is always at a right angle (perpendicular) to the surface, which the object is resting on.
Typically, the normal force is denoted as FN or Fn.
- On a flat horizontal surface, the normal force on an object is the equal to the weight of the object (FN = m.g)
- On an inclined plane, FN = m.g.cosT and is always less than the weight of the object. Likewise, on a horizontal surface, T=0 and cosT=1, hence the normal force is equal to the weight of the object.
This interactive lets you explore the concept of a normal force acting on an object when resting on a horizontal or on an inclined surface.
DIY - Frictional Force on Inclined Surface
Friction (a.k.a frictional force) is a force, which resists the relative motion between two surfaces that are in contact with each other. Typically, the frictional force acts in the direction opposite to the direction of motion.
Dry friction resists the relative motion between two solid surfaces in contact. Dry friction is of two types: static friction between non-moving surfaces, and kinetic (or dynamic) friction between moving surfaces.
An object placed on an inclined plane has a natural tendency to slide down due to gravity, such that steeper the incline, greater the acceleration with which it will slide down. However, the friction between the object surface in contact with the resting surface will resist downward sliding motion. If the static frictional force between the two is greater than the sliding force due to gravity, the object will remain stationary. The frictional force between the two surfaces depends upon their individual roughness and the angle of inclination.
This interactive lets you explore the effect of mass and the angle of inclination on the static friction between different surfaces. It also features a free body diagram (FBD) of the different forces involved. You can investigate the critical angle of inclination for different materials, at which an object overcomes the static frictional force and begins to slide down due to its own weight.
DIY - Effect of Mass on Frictional Force on an Inclined Plane with an FBD
Friction (a.k.a frictional force) is a force, which resists the relative motion between two surfaces that are in contact with each other. Typically, the frictional force acts in the direction opposite to the direction of motion.
Dry friction resists the relative motion between two solid surfaces in contact. Dry friction is of two types: static friction between non-moving surfaces, and kinetic (or dynamic) friction between moving surfaces.
An object placed on an inclined plane has a natural tendency to slide down due to gravity, such that steeper the incline, greater the acceleration with which it will slide down. However, the friction between the object surface in contact with the resting surface will resist downward sliding motion. If the static frictional force between the two is greater than the sliding force due to gravity, the object will remain stationary. The frictional force between the two surfaces depends upon their individual roughness and the angle of inclination.
This interactive lets you explore the effect of mass and the angle of inclination on the static friction between different surfaces. It also features a free body diagram (FBD) of the different forces involved. You can investigate the critical angle of inclination for different materials, at which an object overcomes the static frictional force and begins to slide down due to its own weight.
DIY Simple Electric Circuit Builder 1 - Light Bulbs in Series
An electric circuit is a closed path along which the electrons flow and usually do some useful work such as causing a light bulb to glow or a fan to rotate.
A simple electric circuit consists of a power source (battery), wires, and one or more load devices (resistors) such as light bulbs, buzzers, fans, etc.
When the circuit is closed, electrons flow from the battery, through the wires, into the light bulb and return back to the battery.
Two arrangements of connecting devices in an electric circuit are series and parallel. In a series circuit, devices such as bulbs are connected one after the other, along a single path. In a parallel circuit, two or more bulbs are connected between the same connection points in the circuit, forming parallel branches.
This interactive consists of a simple electric circuit builder, which allows you to build a circuit using a battery, wires and light bulbs, which can be connected in two parallel branches.
DIY Simple Electric Circuit Builder 2 - Light Bulbs in Parallel
An electric circuit is a closed path along which the electrons flow and usually do some useful work such as causing a light bulb to glow or a fan to rotate.
A simple electric circuit consists of a power source (battery), wires, and one or more load devices (resistors) such as light bulbs, buzzers, fans, etc.
When the circuit is closed, electrons flow from the battery, through the wires, into the light bulb and return back to the battery.
Two arrangements of connecting devices in an electric circuit are series and parallel. In a series circuit, devices such as bulbs are connected one after the other, along a single path. In a parallel circuit, two or more bulbs are connected between the same connection points in the circuit, forming parallel branches.
This interactive consists of a simple electric circuit builder, which allows you to build a circuit using a battery, wires and light bulbs, which can be connected in two parallel branches.