The average weight of an athlete should be around 60kg so from the information that the athlete can run 100m in 10s, we can calculate that their average speed is 10m/s. Using the kinetic energy formula, Ek = 1/2mv^2 we can calculate the kinetic energy using 60kg as the mass.
(1/2)(60)(10^2) = Ek
Ek= 3000J
Answer:
5.0 m
Explanation:
The velocity of the object at time t is given by
where a=9.8 m/s^2 is the acceleration of gravity and t is the time. If we substitute v=7 m/s, we can find the time t at which the velocity became 7 m/s:
The height of the object at time t, h(t), is given by the equation
where 
is the initial height. By substituting t=0.71 s inside the equation, we find the height h(t) at which the velocity is 7 m/s:
Your pendulum does a complete swing in 1.9 seconds. You want to SLOW IT DOWN so it takes 2.0 seconds.
Longer pendulums swing slower.
You need to <em>make your pendulum slightly longer</em>.
If your pendulum is hanging by a thread or a thin string, then its speed doesn't depend at all on the weight at the bottom. You can add weight or cut some off, and it won't change the speed a bit.
Acceleration = (27 - 2.3 ) / 9.8 = ....
