High Jump Physics: Leaping 1.55m with 0.70m/s Speed

In summary, the conversation discusses the calculation for the minimum speed an athlete needs to leave the ground in order to lift his center of mass 1.55 m and cross the bar with a speed of 0.70 m/s in the high jump. The formula for kinetic and potential energy is used, but the incorrect answer is given due to not taking the square root.
  • #1
Morgan89
9
0
In the high jump, the kinetic energy of an athlete is transformed into gravitational potential energy without the aid of a pole. With what minimum speed must the athlete leave the ground in order to lift his center of mass 1.55 m and cross the bar with a speed of 0.70 m/s


I have tried solving this problem by using the formulas for kinetic and potential energy. I thought that the initial kinetic energy would equal the potential energy plus the kinetic energy in the air.

KE = PE + KE'
.5(m)(v^2) = m(g)(h) + .5(m)(v^2)
Then i figured i could cancel out mass since it is in all parts
.5(v^2) = (9.81)(1.55) + .5(.7^2)
v= Sqrt (15.205 + .245)
v = 30.9

This is the wrong answer, and i am not sure what i am doing wrong. Please help.
 
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  • #2
Did you actually take the square root? It doesn't look like you did.
 
  • #3
Thank you. that was the problem! Appreciate it!
 

Related to High Jump Physics: Leaping 1.55m with 0.70m/s Speed

What is the physics behind high jump?

The physics behind high jump involves a combination of kinetic and potential energy. The jumper converts their speed into potential energy as they bend their body and lift their center of mass over the bar. The jumper also utilizes the force of gravity and the angle of their takeoff to achieve the necessary height to clear the bar.

How does speed affect high jump?

Speed plays a crucial role in high jump as it determines the amount of kinetic energy the jumper has when approaching the bar. A higher speed allows the jumper to generate more potential energy and clear a higher bar. However, too much speed can also result in a less controlled jump and potentially lead to a failed attempt.

What is the ideal takeoff angle for high jump?

The ideal takeoff angle for high jump is around 45 degrees. This angle allows the jumper to effectively utilize their speed and generate enough height to clear the bar. If the takeoff angle is too steep, the jumper may not have enough horizontal velocity to clear the bar. If the angle is too shallow, the jumper may not have enough height to clear the bar.

How does the athlete's body shape and technique impact their high jump performance?

The athlete's body shape and technique greatly impact their high jump performance. A taller and leaner body type is typically more advantageous for high jump as it allows for a longer stride and more efficient use of energy. Additionally, proper technique, such as the "Fosbury Flop," can help the athlete clear higher bars with less physical effort.

What other factors besides speed and angle affect high jump performance?

Other factors that can affect high jump performance include the jumper's strength, flexibility, and overall physical conditioning. Proper training and technique can also greatly impact an athlete's performance. Environmental conditions, such as wind and temperature, can also play a role in high jump performance.

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