[No.3 The Triple Jump] When is the golden year for the triple jump?
The golden year for the triple jump, IAAF world athletics championships gothenburg 1995
The triple jump event is a three-step jump, a hop, step and jump. It is believed to have derived from an ancient Irish sport to traverse a water paddle with the least steps.
The basic rule is to jump the first hop and the second step on the same foot. If an athlete takes off on their right foot, the step is with the same foot, then the final jump is kicked off with the left foot. If the athlete launches on their left foot, then the foot sequence is left, left then right. In major high-level competitions, a takeoff board is set, from the nearer end of the sand pit, at 13 meters for men and 10 meters for women, so that the jump landing will be in the sand pit.
The world record for the triple jump is 18.29 meters, achieved by Jonathan Edwards at IAAF World Athletics Championships Gothenburg 1995, Sweden. He made the 18 meter mark in his first jump, the first ever in human history, then in his second jump, he broke this record by jumping 18.29 meters, creating great excitement in the stadium.
Three days later in the women’s triple jump, Inessa Kravets made a new world record of 15.50 meters. So 1995 proved to be the golden year for triple jump world records.
The ideal takeoff angle generated by the kick-off timing
In the triple jump, Japanese athletes had the great achievement of winning three consecutive Olympic Games in 1928, 1932 and 1936. Requiring physical strength in the legs to withstand three jumps and a takeoff technique different from that of the long jump, the triple jump was an event that could be won by shorter athletes such as the Japanese.
In general, the major technical points in jumping events are the approach and takeoff, but the takeoff angle differs from one event to another.
Take a super-sized vaulting box (sometimes referred to as a monster box) for example, an athlete kicks off backwards in order to convert the forward momentum built up during the run up. In this way, the net force of the approach and takeoff results in an upward direction, enabling the athlete to jump over a vault that is higher than their own height.
In the triple jump however, jumping upward will not help gain horizontal distance. The takeoff is executed at the moment when the backward position of the body, when the foot is set on the takeoff board, shifts forward, kicking off in the direction of projection. This moment lasts only 0.1 to 0.2 seconds. It is often the case that athletes fail to make sufficient distance without committing a foul because they missed this timing.
Similarly, unlike the long jump in which the momentum accumulated through the approach and takeoff is focused on a single jump (the world record is 8.95 meters), the triple jump requires an optimal distribution of the energy between the hop, step, and jump phases. In Edwards’ world record jump, the 18.29 meters was divided into 6.05, 5.22 and 7.02 meters, thus the distribution is about 33%, 29%, and 38%, respectively.
Normally, the proportion of the hop is in inverse proportion to the jump phase while the step phase relatively stays the same. Therefore, the overall distance may be enhanced by increasing the mileage of the step phase. The jump that achieves a great distance is rhythmical, with a beautiful action in the air throughout the three phases of hop, step, and jump. A well distributed balance between speed and jumping action is the key to a successful triple jump.
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Cars with manual transmission (MT) have a mechanism to shift gears manually from the first gear to second and drive (third gear).
Starting the engine requires a large amount of torque, but the engine’s mechanism is not suitable for accelerating from start-up. For this reason, it starts on a large gear to gain the initial momentum reliably, and shifts to smaller gears as sufficient velocity is attained. A failure shifting gears may result in the engine stalling. This troublesome gear-shifting is automated in cars with an automatic transmission (AT) system.
As electric motors are characteristically capable of achieving greater start-up torque, hybrid electric vehicles (HEV) employ an electric motor to start and then use the combustion engine for driving.
The motor serves as a power generator when the vehicle is slowing down or cruising, converting the energy generated by the brakes into electricity and charging the battery. This improves the fuel efficiency and reduces exhaust gas emissions.
The magnet used in the drive motor also contributes to improved fuel efficiency in HEVs. Mainstream models use a synchronous motor with a magnet embedded in the rotor (IPM).
High-performance magnets can facilitate reductions in the size and weight of the motor and enhanced efficiency. Being employed in a high temperature environment, the drive motor for a HEV also needs to have high heat resistance.
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