Topic: Weightlifting question in Physics textbook

[Shaun Le Conte]

I am not a student of physics but I was searching for S. Didyk's weightlifting achievements and found this question. It's searchable on google, but if you fancy physics maybe give the question a try.

Q. A world weightlifting record is held by Sergei Didyk of the USSR. He lifted 261 kg to a height of 2.3m in 4s. Find (i) the weight lifted by Didyk, (ii) the work done by him and (iii) the power developed by him 

The text says to assume g = 10 m/s^2 but isn't it easy enough to assume it's 9.8 m/s^2?

The text is Together with Physics, published in India and containing past year papers to ICSE exams.

[Matt Erdman]

The answer is 261 

Sergey Didyk 261 kg Clean and Jerk

[Arturo Gómez]

weight =261x g
work = weight x (final height - initial height)
power = work/ time

But the work and th power calculated are only the correspondent to the mechanical work made by the gravitational force over the bar. Because the work related to stabilization, biological process, and heat dissipation, increased by the lift, are not included in the problem.

This relativize the habitual way of coaches of sum litfts as estimate the work

[Arturo Gómez]

And another phisical and mechanical question is that he doesn´t (like Alexeev and Taranenko) kick with the head infront when he finish the jerk. I overlight this.