Question

Nowdothesameproblemwiththepivotatthe toes. A Ballet dancer puts all her weight on the toes of one foot. If her mass is 60 kg, what is the force that has to be exerted by her leg muscle to hold that pose? Assume the pivot is at the toes.

Answer 1

The force is
`F = 2400 \ N`

Step-by-step explanation:

The diagram for this question is shown on the first uploaded image

From the question we are told that

The mass of the dancer is
`m_d = 60 \ kg`

From the diagram the

The first distance is
`l_1 = 20 \ cm`

The second distance is
`l_2 = 5 \ cm`

At equilibrium the moment about the center of the dancers feet is mathematically represented as

`F * l_2 - (mg* l_1)`

Where
`g= 10 \ m/s^2`

substituting values

`F * 5 - (60* 9.8 * 20)`

=>
`F = (60 * 10 * 30)/(5)`

=>
`F = 2400 \ N`