# Answer to Question #4887 in Mechanics | Relativity for lizzeth

Question #4887

Shawn and his bike have a total mass of 47.5 kg. Shawn rides his bike 0.64 km in 12.9 min at a constant velocity.

The acceleration of gravity is 9.8 m/s2 . What is Shawn’s kinetic energy?

Answerinunitsof J

The acceleration of gravity is 9.8 m/s2 . What is Shawn’s kinetic energy?

Answerinunitsof J

Expert's answer

Kinetic energy is described by the following formula

Ek=mv^2/2

where m - mass of an object (in our case it's mass of Shawn and his bike)

v - velocity of an object ( in our case it's velocity with which Shawn rides his bike)

velocity was constant during ride hence we can find it as v= S/T=0.64*1000/12.9*60=0.83 m/s

Hence we can substitute values into the formula

Ek=47.5*0.83^2/2=16.36 J

Ek=mv^2/2

where m - mass of an object (in our case it's mass of Shawn and his bike)

v - velocity of an object ( in our case it's velocity with which Shawn rides his bike)

velocity was constant during ride hence we can find it as v= S/T=0.64*1000/12.9*60=0.83 m/s

Hence we can substitute values into the formula

Ek=47.5*0.83^2/2=16.36 J

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