Motion & Mechanics

A:

The momentum of pushing water backwards propels swimmers forward in the water, thereby creating kinetic energy in the water that goes backwards and produces forward movement. A swimmer's hands and feet provide lift and backward momentum in the water. Swimmers' hands act similarly to an airplane wing moving through air, except hands are like hydrofoils moving through water.

See Full Answer
Filed Under:
  • How do bullet trains work?

    Q: How do bullet trains work?

    A: Bullet trains, also called maglev trains, operate with magnetic levitation technology developed by Japanese and German engineers. Japanese engineers refer to their method as electrodynamic suspension while German engineers refer to their method as electromagnetic suspension. Either way, magnets raise the trains above the track, which means there is no need for wheels.
    See Full Answer
    Filed Under:
  • What is the definition of input force?

    Q: What is the definition of input force?

    A: Input force is the initial force used to get a machine to begin working. Machines are designed to increase the input force for a larger output force.
    See Full Answer
    Filed Under:
  • Why can't liquids be compressed?

    Q: Why can't liquids be compressed?

    A: Liquid compression is difficult but not impossible because they feature a mid-level intermolecular force that makes their molecules difficult to compress. Intermolecular force is the strength used to hold molecules tightly together or force them apart. The strength of the intermolecular force depends on the state of the matter, with solids having the strongest intermolecular force and gases having the weakest intermolecular force.
    See Full Answer
    Filed Under:
  • What are some achievements of Isaac Newton?

    Q: What are some achievements of Isaac Newton?

    A: Some of Sir Isaac Newton's achievements include defining the law of gravity and the three laws of motion, inventing the reflecting telescope, defining theories of light and color and inventing calculus. Newton was a philosopher, mathematician and physicist who played an important role in the scientific Revolution of the 17th century.
    See Full Answer
    Filed Under:
  • What is an example of elastic force?

    Q: What is an example of elastic force?

    A: An example of elastic force is bungee jumping. The elastic cord creates resistance and imposes a force when the cord is stretched far enough. That elasticity creates the bouncing motion a bungee jumper feels after the initial jump, while the cord works to return to its normal size.
    See Full Answer
    Filed Under:
  • What is the definition of hydraulic pressure?

    Q: What is the definition of hydraulic pressure?

    A: The definition of hydraulic pressure is that of a force per unit area that is measured in pounds per square inch (PSI). Dynamic pressure and static pressure are the two pressure components.
    See Full Answer
    Filed Under:
  • Why do humans float in water?

    Q: Why do humans float in water?

    A: Any body in water floats or sinks depending on the buoyant forces that push it up and the gravity that pulls it down. If the body is heavier than the water it displaces, it sinks. If the water the body displaces is heavier, then the body floats.
    See Full Answer
    Filed Under:
  • What is the law of the pendulum?

    Q: What is the law of the pendulum?

    A: The law of the pendulum, discovered by Galileo Galilei, states that swinging objects follow the same path and have a period between swings that remains constant. Galileo attracted immediate attention for the discovery, which was later used in clock regulation.
    See Full Answer
    Filed Under:
  • What are the main branches of mechanics?

    Q: What are the main branches of mechanics?

    A: The two main branches of mechanics are statics and dynamics. Static mechanics is the study of forces which are required to keep a body in equilibrium. Dynamics is the study of motion itself, and the forces producing it.
    See Full Answer
    Filed Under:
  • How does streamlining reduce air resistance?

    Q: How does streamlining reduce air resistance?

    A: Streamlining reduces air resistance by providing a smooth surface over which air flows easily and uniformly. Without streamlining, eddies formed on the trailing edges of objects create turbulent, low-pressure areas and increase air resistance, also known as drag.
    See Full Answer
    Filed Under:
  • What is gravitational energy?

    Q: What is gravitational energy?

    A: Gravitational energy is the movement of an object or mass that is caused by the pull of gravity. This is caused on Earth by the strong attraction of all other masses to be drawn back to Earth's center. An example of gravitational energy is water from a river tumbling over a cliff to form a waterfall.
    See Full Answer
    Filed Under:
  • How much pressure can an egg withstand?

    Q: How much pressure can an egg withstand?

    A: An experiment conducted at the Science Studio at Imagination Station demonstrated that a single egg was able to withstand at least 3.75 pounds of force. Eggs are most resistant to breaking when pressure is applied to their ends.
    See Full Answer
    Filed Under:
  • Is air considered a fluid?

    Q: Is air considered a fluid?

    A: Air is a fluid because the force needed to deform it depends on how fast it is deformed, not on how much it is deformed. This differs from a solid, where the force needed to deform it remains the same whether it is done quickly or slowly.
    See Full Answer
    Filed Under:
  • Does length affect the period of a pendulum?

    Q: Does length affect the period of a pendulum?

    A: The length of the pendulum is directly correlated to its period as per the pendulum equation: T = 2π√(L/g), where T is the period of the pendulum, L is its length, and g is the gravitational constant 9.8 m/s2. Regardless of the weight of the pendulum bob, otherwise known as the weight at the end of the string, the deciding factor of the period of the swing is length, as it is the only variable in the stated equation.
    See Full Answer
    Filed Under:
  • What are types of potential energy?

    Q: What are types of potential energy?

    A: Potential energy is the stored energy of an object that has the potential to change to a different form of energy to do work. The types of potential energy are gravitational, elastic, chemical, electric and nuclear.
    See Full Answer
    Filed Under:
  • What is the meaning of "swept volume"?

    Q: What is the meaning of "swept volume"?

    A: "Swept volume" is defined as the volume of fluid through which a piston or plunger moves when it makes a stroke in an engine, according to Oxford Dictionaries. The swept volume times the number of cylinders in an engine is known as the displacement, usually measured in liters. Calculating the swept volume is done by multiplying pi times the radius squared times the height of the chamber.
    See Full Answer
    Filed Under:
  • What is the law of acceleration?

    Q: What is the law of acceleration?

    A: The law of acceleration is formally referred to as Newton's Second Law of Motion and defines the rate of acceleration as a product of the force exerted on the object and the mass of the object. The rate of acceleration increases as the net force increases. The inverse is true for mass, with the acceleration decreasing as the mass increases.
    See Full Answer
    Filed Under:
  • How did Newton discover gravity?

    Q: How did Newton discover gravity?

    A: Sir Isaac Newton discovered gravity around 1665 while he was drinking tea and observed an apple falling from a tree. Newton deduced that the force that caused the apple to fall to the ground also is the same force that causes the moon to orbit the earth.
    See Full Answer
    Filed Under:
  • Why do some objects float in water and others sink?

    Q: Why do some objects float in water and others sink?

    A: Objects comprised of material that is denser than water tend to sink; objects with a lighter density tend to float. Since air is lighter than water, hollow objects can float if their total density is less than water. Preventing objects from absorbing water is important.
    See Full Answer
    Filed Under:
  • Why is rolling friction much less forceful than sliding friction?

    Q: Why is rolling friction much less forceful than sliding friction?

    A: When an object slides across the ground, it has much more surface area in direct contact with the ground, which means that the amount of friction is significantly higher. When an object rolls along the ground, only a minuscule point on the object contacts the ground at any point in time, making the stopping force much weaker.
    See Full Answer
    Filed Under:
  • What is a Venturi meter?

    Q: What is a Venturi meter?

    A: A Venturi meter is a flow measurement device, commonly utilized in the water supply industry. A Venturi meter specifically uses a converging section of pipe to increase flow velocity. A corresponding reduction in pressure permits a determination of the flow rate.
    See Full Answer
    Filed Under: