Enter the coordinate system relative to which you will determine the direction and module speed .If the problem is already defined formula speed depending on the time, enter the coordinate system is not necessary - it is assumed that it already is.
on available functions depending speed from time to time you can find the value speed at any time t.Suppose, for example, v = 2t² + 5t-3.If you want to find module rate at time t = 1, simply substitute this value into the equation and calculate the v: v = 2 + 5-3 = 4.
When a task requires finding the velocity at the initial time, substitute in the function t = 0.Likewise, you can find the time, substituting a certain speed.Thus, at the end of the path body is stopped, that is, its speed has become zero.Then 2t² + 5t-3 = 0.F
rom t = [- 5 ± √ (25 + 24)] / 4 = [- 5 ± 7] / 4.It turns out that either t = -3, t = a 1/2, and since the time can not be negative, there is only t = 1/2.
Sometimes problems speed equation given in a veiled form.For example, in the condition it is said that the body moved uniformly accelerated with a negative acceleration of -2 m / s², and initially the speed of the body was 10 m / s.The negative acceleration means that the body is uniformly slowed.Because of these conditions, you can create an equation for the speed : v = 10-2t.With every second the rate will be reduced to 2 m / s, until the body stops.At the end of the road speed is reset, so it's easy to find the total drive time: 10-2t = 0, where t = 5 seconds.5 seconds after the beginning of the movement the body stops.
addition to linear motion of the body, there is also a movement of the body in a circle.In general, it is curved.There arises a centripetal acceleration that is associated with the linear velocity of the formula a (c) = v² / R, where R - radius.It is convenient to consider also the angular velocity ω, and v = ωR.
- how to find the way from the time dependence