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Modfied: |
| Work, Power, & Energy Objectives:
A pole vaulter uses the relationship between mechanical work and energy. Work is the product of force and displacement. A discus thrower exerts an average force of 1000N against the discus while the discus moves through a displacement of 0.6m in the direction of the force. How much work did the thrower do on the discus? How much work does a weightlifter do? Energy is the capacity to do work
Why does a high jumper use a run-up? Why did a shot putters starting postion change?
U = ΔGPE + ΔKE + ΔSE Work & energy in the javelin Question: If a softball pitcher wants to be able to pitch 60 mph (27 m/s), how much force should she train with (Assume she pushes the 0.185 kg ball through a displacement of 3.5 m during the pitch). Conservation of Mechanical Energy The total mechanical energy of an object is conserved if no external forces act on the object other than gravity or the resultant force is zero. Which of the following situations would have conservation of mechanical energy?
Power is the rate of doing work (measured in Watts) P = U/t or P = F(v) In a vertical jump test, a 60-kg student jumps 60 cm, whereas a 90-kg student jumps 45 cm. Assuming both jumpers applied force the ground for the same amount of time, which jumper was more powerful? |
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