Skating on Ice

Torque is what allows a figure skater to skate on ice. A skater pushes one of his/her feet against the ice in order to exert a torque on his/her body and thereby initiates a spin.

Designing a Door

Torque has to be taken into account in the design and creation of a door. Because the torque of a force is greater when it is applied along a larger distance from the axis of rotation (and therefore the force is more effective) door knobs are placed on the side opposite the door hinges.

Torque, Clarified

It is important to note that torque is not always determined by the total force applied on an object. Instead, it is only the force that is perpendicular to the lever arm that is taken into account in the calculation.

Torque (cont)

The torque of a force is found using this simple formula:
T = Fd, which means that the torque equals the distance from the axis of rotation to the place where the force is applied (d) multiplied by the magnitude of the force (F). Maximizing the torque of a force has many real-world benefits, so being able to calculate it is beneficial.

Earth's Gravitational Pull

In addition to cannonizing his three laws of motion, Newton also created the Law of Universal Gravitation, which makes it possible to determine the force of gravity between two bodies, such as the Earth and the moon.

Tension

 Tension is a type of contact force which exists in a string, rope, wire, or cable when it is being pulled, specifically on both of its ends. In opposition to being pulled, the string applies an equal tension force on the objects, pulling them towards itself.

Tension is a vector, and therefore has a direction and a magnitude.

The force itself is called a tension force because the rope is in a state of tension.

Mousetrap Car

It is possible to create a car out of a common household mousetrap. How you ask? By attaching wheels to the moustrap, the turn of the back axel, which initiates the motion of the car, can be caused by the snap of trap.

Law of Acceleration

Remember that Newton's first law stated that an object with no net force acting on it will not accelerate. Newton's second law of motion, though, states that an unbalanced force (one that is not equally opposed by another force) acting on an object will cause the object to accelerate. The object's mass, which measures its inertia, also determines how much the object's movement will change. From this, Newton derived the formula a= F/m, where acceleration is directly proportional to force and inversely proportional to object mass. 

"What goes up, must come down."

Gravity causes my dog to land on the ground seconds after he jumps, rather than continuing to gain height.

Gravity. What is it, exactly? Well, gravity is the name of the force that pulls objects towards the Earth's core- it's the reason that objects stay within Earth's atmosphere. This force has different magnitudes for different large objects. Since gravity is related to object mass, the pull of gravity on Earth is stronger than the one felt on the moon, for example. On Earth, the numerical constant for gravity is 9.81 m/s^2, or about 32 ft/s^2.