you need
  • - scales;
  • - speedometer or radar;
  • - protractor.
Determine the mass of the body using weights or any other method.If the body is on a horizontal surface (and it is unimportant, it is moving or is in a state of rest), the reaction force equal to the force of gravity acting on the body.To calculate it, multiply the body weight on the acceleration of gravity, which is equal to 9.81 m / s² N = m • g.
When the body moves along an inclined plane at an angle to the horizontal reaction force is at an angle to the force of gravity.However, it will only compensate the gravity force component which acts perpendicularly to the inclined plane.To calculate th
e floor reaction force using protractor to measure the angle of the plane is on the horizon.Calculate floor reaction force, multiplying the weight by the gravitational acceleration and the cosine of the angle at which the plane of the horizon is N = m • g • Cos (α).
In that case, if the body moves over the surface, which is a part of a circle with a radius R, such bridge hillock the reaction force takes into account the force acting in the direction of the center of the circle, with the acceleration,equal centripetal acting on the body.To calculate the floor reaction force at the top, from the gravitational acceleration subtract the square of the speed ratio of the radius of curvature of the trajectory.
get the number, multiply the mass of moving bodies N = m • (g-v² / R).The speed must be measured in meters per second, and the radius in meters.At a certain speed acceleration value from the center of the circle, can equal or even exceed the acceleration of free fall, at which point the clutch body to the surface disappear, so, for example, motorists need to closely monitor the speed on these sections of the road.
If the curvature is directed downward, and the trajectory of the body is concave, then calculate the floor reaction force, adding to the acceleration of free fall of the ratio of the square of speed and radius of curvature of the trajectory, and the result obtained multiply by the body weight of N = m •(g + v² / R).
If you know the friction force and coefficient of friction, the floor reaction force calculated by dividing the frictional force by the factor N = Ftr / μ.