At a body throw up it slows down with acceleration of g≈9.8 of m/s², the caused gravitational attraction of Earth. For this reason in some timepoint the thrown body stops and begins the movement in the opposite direction, down. The distance from a point of change of the direction of the movement of a body to the Earth's surface will also be to equally maximum height of rise.
It is required to you
- - stop watch;
- - radar;
- - calculator;
- - angle meter.
Instruction
1. Find the maximum height of raising of a body, it is thrown by means of a stop watch up. Does not matter whether the body vertically up or at an angle to the horizon is thrown. By means of a stop watch, note time which the body was in flight. Measure value of time in seconds. As a half of time spent in flight a body rises, falls to the second half, divide the received value into 2.
2. Calculate the maximum height of raising of a body of N. For this purpose build t divided into the 2nd time of flight in a square. Increase the received value by the acceleration of gravity of g≈9.8 of m/s², and divide result into number 2, H=g∙t²/2. Receive height in meters.
3. Example. After a throw from the Earth's surface the body fell to it through 4 again with by what maximum height it rose? Find time of raising of a body for the maximum height. It is equal to a half of all time of movement 4/2=2 of page. Substitute value in a formula H=g∙t²/2=9.8∙2²/2≈20 to m. If the increased accuracy is not required, the value of acceleration of gravity can be taken 10 m/s².
4. Determine the maximum height of raising of a body if its initial speed is known. It can be measured by the special radar. In some devices, it is initially known. In case the body is started vertically up with an initial speed of v0 to find the maximum height of raising of this body divide a square of this initial speed into the doubled value of acceleration of gravity, H=v0²/2∙g. Speed has to be measured in meters per second.
5. Find the maximum height of raising of a body which initial speed of v0 is directed at an angle to the horizon. When calculating consider that only the vertical component of speed which is equal to v0y = to v0∙sin(α) where α – it measure a corner to the horizon under which the body began the movement by the angle meter is responsible for raising of a body. Then for calculation of the maximum height of raising of a body it is possible to use the formula described in the previous point, and the turned-out result will increase by a sine α, the squared H= (v0²/2∙g) ∙sin² (α).