Question 172: Work, Energy and Power & Circular Motion

Question

An athlete in the olympic games covers a distance of $$100$$ $$m$$ in $$10$$ $$s.$$ His kinetic energy can be estimated to be in the range

Accepted Answer

The average speed of the athelete
$$v = {{100} \over {10}} = 10m/s\,\,\,\,$$ $$	herefore$$ $$K.E. = {1 \over 2}m{v^2}$$
If mass of athlete is $$40$$ $$kg$$ then, $$K.E.$$ $$ = {1 \over 2} 	imes 40 	imes {\left( {10} ight)^2} = 2000J$$
If mass of athlete is $$100$$ $$kg$$ then, $$K.E.$$ $$ = {1 \over 2} 	imes 100 	imes {\left( {10} ight)^2} = 5000J$$
His kinetic energy can be in the range = 2000 J to 5000 J.

Answer

$$200J-500J$$

Answer

$$2 	imes {10^5}J - 3 	imes {10^5}J$$

Answer

$$20,000J - 50,000J$$

Answer

$$2,000J - 5,000J$$

Work, Energy and Power & Circular Motion

An athlete in the olympic games covers a distance of $100 m in 10 s.$ His kinetic energy can be estimated to be in the range

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