- rangefinder, scales, speedometer or the radar, ruler, stopwatch.
Determination of air resistance falls uniformly Measure body weight with the help of weights.Reset it to a certain height in until it moves smoothly.Multiply the weight in kilograms by the acceleration due to gravity (9.81 m / s²), the result is the force of gravity acting on the body.And as it moves uniformly in a straight line, the force of gravity is equal to the force of air resistance.
Determination of air resistance body
, gaining weight skorostOpredelite using weights.After the body began to move, with the help of a speedometer or radar to measure the speed of its instant start.At the end portion of the final measure its instantaneous speed.Speed is measured in meters per second.If the instruments measure it in kilometers per hour, divide the value by 3.6.In parallel, using a stopwatch, determine the time during which the change occurred.Subtracting from the finite speed of the start and share the results on time, get the acceleration with which the body moves.Then find the force that causes the body to change the speed.If the body falls, it is the force of gravity when the body moves horizontally - the thrust of the engine.From this power subtract the product of body mass by its acceleration (Fc = F + m • a).This will be the force of air resistance.It is important that when moving the body does not touch the ground, for example, moving hovercraft or falls down.
Determination of air resistance body falling from vysotyIzmerte weight and drop it from a height, which is known in advance.Upon contact with the ground speed lock body via a speedometer or radar.Then find the product of the gravitational acceleration of 9.81 m / s² on the height from which a falling body, subtract from this value the speed squared.The result multiply by the body weight and divide it by the height from which it fell (Fc = m • (9,81 • H-v²) / H).This will be the force of air resistance.
In general, the power of resistance can be found, if the air density multiplied by the square of the speed with which the body moves, divide that value by 2 and multiplied by the area of the body perpendicular to the direction of the velocity.The result is multiplied by the aerodynamic coefficient, which is determined experimentally.Therefore, application of this formula is complicated.